# Co–Ta phases

> Co–Ta system: 19 phases (tier A 12, tier C 2, liquid 1, needs_review 4); 18 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references.

HTML: https://data.orchid-project.org/phases/pages/CO-TA.html · Markdown: https://data.orchid-project.org/phases/pages/CO-TA.md

19 phases (tier A 12, tier C 2, liquid 1, needs_review 4); 18 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: [interactive registry](https://orchid-project.org/phases/?q=CO-TA) · [full JSON](https://data.orchid-project.org/phases/systems/CO-TA.json) · [Co–Ta system page](https://data.orchid-project.org/systems/CO-TA.html) · [Markdown](https://data.orchid-project.org/phases/pages/CO-TA.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Co–Ta system (19)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BCC_A2](#phase-co-ta-bcc-a2); _phase:co-ta:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–4000 K, x(Ta) 0.8606–1 | 12 | 6 |
| [C14_LAVES](#phase-co-ta-c14-laves); _phase:co-ta:c14-laves_ | MgZn2 · C14 · hP12 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 1403.36–1840 K, x(Ta) 0.36178–0.36323 | 4 | 1 |
| [C15_LAVES](#phase-co-ta-c15-laves); _phase:co-ta:c15-laves_ | Cu2Mg · C15 · cF24 · Fd-3m (227) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1895.72 K, x(Ta) 0.28736–0.33892 | 11 | 2 |
| [C36_LAVES](#phase-co-ta-c36-laves); _phase:co-ta:c36-laves_ | MgNi2 · C36 · hP24 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1727.19 K, x(Ta) 0.24578–0.27082 | 9 | 1 |
| [CO16TA9_C14](#phase-co-ta-co16ta9-c14); _phase:co-ta:co16ta9-c14_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 1320–1840 K, x(Ta) 0.36–0.36 | 0 | 1 |
| [CO2TA_C14](#phase-co-ta-co2ta-c14); _phase:co-ta:co2ta-c14_ | MgZn2 · C14 · hP12 · P6_3/mmc (194) | tier A: standard phase name | stable in 4 of 4 calculated diagram(s): 1538.23–1864.11 K, x(Ta) 0.35991–0.37341 | 16 | 4 |
| [CO2TA_C15](#phase-co-ta-co2ta-c15); _phase:co-ta:co2ta-c15_ | Cu2Mg · C15 · cF24 · Fd-3m (227) | tier A: standard phase name | stable in 4 of 4 calculated diagram(s): 300–1923.45 K, x(Ta) 0.25891–0.3451 | 24 | 4 |
| [CO2TA_C36](#phase-co-ta-co2ta-c36); _phase:co-ta:co2ta-c36_ | MgNi2 · C36 · hP24 · P6_3/mmc (194) | tier A: standard phase name | stable in 4 of 4 calculated diagram(s): 1220.39–1850 K, x(Ta) 0.22511–0.2713 | 21 | 4 |
| [CO3TA](#phase-co-ta-co3ta); _phase:co-ta:co3ta_ | BaPb3 · hR12 · R-3m (166) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1320.39 K, x(Ta) 0.2363–0.25 | 0 | 1 |
| [CO3TA_C36](#phase-co-ta-co3ta-c36); _phase:co-ta:co3ta-c36_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1720.72 K, x(Ta) 0.25–0.25 | 0 | 1 |
| [CO7TA2](#phase-co-ta-co7ta2); _phase:co-ta:co7ta2_ | BaPb3 · hR12 · R-3m (166) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 5 of 5 calculated diagram(s): 300–1316.43 K, x(Ta) 0.22222–0.22222 | 16 | 5 |
| [COTA2_C16](#phase-co-ta-cota2-c16); _phase:co-ta:cota2-c16_ | Al2Cu · C16 · tI12 · I4/mcm (140) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–2225.5 K, x(Ta) 0.62275–0.68661 | 19 | 6 |
| [MU_D85](#phase-co-ta-d85-mu); _phase:co-ta:d85-mu_ | Fe7W6 · D8_5 · hR13 · R-3m (166) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–2045.23 K, x(Ta) 0.44838–0.55701 | 38 | 6 |
| [DIS_MU](#phase-co-ta-dis-mu); _phase:co-ta:dis-mu_ |  | needs_review | not stable in 1 calculated diagram(s) | 0 | 1 |
| [FCC_4SL](#phase-co-ta-fcc-4sl); _phase:co-ta:fcc-4sl_ |  | needs_review | stable in 2 of 2 calculated diagram(s): 691.7–1769.38 K, x(Ta) 0–0.05936 | 0 | 2 |
| [FCC_A1](#phase-co-ta-fcc-a1); _phase:co-ta:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 621.48–1777.64 K, x(Ta) 0–0.05936 | 24 | 9 |
| [L12_FCC](#phase-co-ta-fcc-l12); _phase:co-ta:fcc-l12_ | AuCu3 · L1_2 · cP4 · Pm-3m (221) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 671.48–1773.65 K, x(Ta) 0–0.05927 | 10 | 1 |
| [HCP_A3](#phase-co-ta-hcp-a3); _phase:co-ta:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–729.98 K, x(Ta) 0–0.01216 | 5 | 6 |
| [LIQUID](#phase-co-ta-liquid); _phase:co-ta:liquid_ | liquid | liquid | stable in 6 of 6 calculated diagram(s): 1552.64–4000 K, x(Ta) 0–1 | 54 | 6 |

## BCC_A2 (Co–Ta)

- Id: `phase:co-ta:bcc-a2`; status `assigned`
- Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high
- Stability: stable in 6 of 6 calculated diagram(s): 300–4000 K, x(Ta) 0.8606–1
- Literature: 12 values (12 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:bcc-a2)

Names (10): _corpus: _corpus:phase:co-ta:bcc-a2  
_paper: _paper:10.1016/j.calphad.2018.12.002:BCC, paper:10.1016/j.jallcom.2022.166723:bcc, paper:10.1016/s0364-5916(00)00005-5:bcc  
_tdb: _tdb:CoTa-02Har.tdb:BCC_A2, tdb:CoTa-14Shi.tdb:BCC_A2, tdb:CoTa-19Wan.tdb:BCC_A2, tdb:CoTa-19Zho.tdb:BCC_A2, tdb:CoTa-22Wan.tdb:BCC_A2, tdb:CoTa-99Liu-LB.tdb:BCC_A2  


### TDB models of BCC_A2 (6): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): BCC_A2, type code %B, sha256 `c7251b1bb94512ab…`

~~~~text
34: PHASE BCC_A2 %B 2 1 3 !
35: CONST BCC_A2 : CO TA% : VA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): BCC_A2, type code %B, sha256 `e4d873cf93726ad0…`

~~~~text
43: PHASE BCC_A2 %B 2 1 3 !
44: CONST BCC_A2 : CO TA% : VA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): BCC_A2, type code %B, sha256 `0188b050430162f4…`

~~~~text
44: PHASE BCC_A2 %B 2 1 3 !
45: CONST BCC_A2 : CO TA% : VA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): BCC_A2, type code %B, sha256 `f38abf64bd567e76…`

~~~~text
48: PHASE BCC_A2 %B 2 1 3 !
49: CONST BCC_A2 : CO TA% : VA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): BCC_A2, type code %B, sha256 `cab3db05a3994913…`

~~~~text
36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : CO TA% : VA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): BCC_A2, type code %B, sha256 `2d4f912a1ca1b737…`

~~~~text
30: PHASE BCC_A2 %B 2 1 3 !
31: CONST BCC_A2 : CO TA% : VA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## C14_LAVES (Co–Ta)

- Id: `phase:co-ta:c14-laves`; status `assigned`
- Structure: MgZn2 · C14 · hP12 · P6_3/mmc (194); type `st:c14-mgzn2-hp12`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-99Liu-LB.tdb also describes the disordered state
- Stability: stable in 1 of 1 calculated diagram(s): 1403.36–1840 K, x(Ta) 0.36178–0.36323
- Literature: 4 values (4 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:c14-laves)

Names (3): _corpus: _corpus:phase:co-ta:c14-laves  
_paper: _paper:10.1016/s0364-5916(00)00005-5:C14  
_tdb: _tdb:CoTa-99Liu-LB.tdb:C14_LAVES  


### TDB models of C14_LAVES (1): PHASE and CONSTITUENT statements as written

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): C14_LAVES, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
45: PHASE C14_LAVES % 2 2 1  !
46: CONST C14_LAVES : CO% TA : CO TA% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_

## C15_LAVES (Co–Ta)

- Id: `phase:co-ta:c15-laves`; status `assigned`
- Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type `st:c15-cu2mg-cf24`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-02Har.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-99Liu-LB.tdb also describes the disordered state
- Stability: stable in 2 of 2 calculated diagram(s): 300–1895.72 K, x(Ta) 0.28736–0.33892
- Literature: 11 values (11 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:c15-laves)

Names (4): _corpus: _corpus:phase:co-ta:c15-laves  
_paper: _paper:10.1016/s0364-5916(00)00005-5:C15  
_tdb: _tdb:CoTa-02Har.tdb:C15_LAVES, tdb:CoTa-99Liu-LB.tdb:C15_LAVES  


### TDB models of C15_LAVES (2): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): C15_LAVES, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
54: PHASE C15_LAVES % 2 2 1  !
55: CONST C15_LAVES : CO% TA : CO TA% : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): C15_LAVES, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
50: PHASE C15_LAVES % 2 2 1  !
51: CONST C15_LAVES : CO% TA : CO TA% : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## C36_LAVES (Co–Ta)

- Id: `phase:co-ta:c36-laves`; status `assigned`
- Structure: MgNi2 · C36 · hP24 · P6_3/mmc (194); type `st:c36-mgni2-hp24`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-99Liu-LB.tdb also describes the disordered state
- Stability: stable in 1 of 1 calculated diagram(s): 300–1727.19 K, x(Ta) 0.24578–0.27082
- Literature: 9 values (9 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:c36-laves)

Names (3): _corpus: _corpus:phase:co-ta:c36-laves  
_paper: _paper:10.1016/s0364-5916(00)00005-5:C36  
_tdb: _tdb:CoTa-99Liu-LB.tdb:C36_LAVES  


### TDB models of C36_LAVES (1): PHASE and CONSTITUENT statements as written

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): C36_LAVES, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
55: PHASE C36_LAVES % 2 2 1  !
56: CONST C36_LAVES : CO% TA : CO TA% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_

## CO16TA9_C14 (Co–Ta)

- Id: `phase:co-ta:co16ta9-c14`; status `needs_review`
- No structure assigned. Why: assessment_declared_blocked_by:stoichiometry_contradicts_C14; stoichiometry_contradicts_C14:CoTa-02Har.tdb
- Candidate (name_token): MgZn2 · C14 · hP12 · P6_3/mmc (194) — Strukturbericht/word 'C14' in the TDB name
- Candidate (sgte_mmc2): MgZn2 · C14 · hP12 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CO16TA9_C14: Co16Ta9
- Candidate (tdb_comment): MgZn2 · hP12 · P6_3/mmc — CoTa-02Har.tdb: 'Prototype MgZn2 (hP12, P6_3/mmc)'
- Stoichiometry: Co 0.6400, Ta 0.3600
- Stability: stable in 1 of 1 calculated diagram(s): 1320–1840 K, x(Ta) 0.36–0.36
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co16ta9-c14)

Names (2): _corpus: _corpus:phase:co-ta:co16ta9-c14  
_tdb: _tdb:CoTa-02Har.tdb:CO16TA9_C14  


### TDB models of CO16TA9_C14 (1): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): CO16TA9_C14, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
59: PHASE CO16TA9_C14 % 2 16 9  !
60: CONST CO16TA9_C14 : CO : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## CO2TA_C14 (Co–Ta)

- Id: `phase:co-ta:co2ta-c14`; status `assigned`
- Structure: MgZn2 · C14 · hP12 · P6_3/mmc (194); type `st:c14-mgzn2-hp12`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-14Shi.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Zho.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-22Wan.tdb also describes the disordered state
- Stability: stable in 4 of 4 calculated diagram(s): 1538.23–1864.11 K, x(Ta) 0.35991–0.37341
- Literature: 16 values (16 accepted) from 2 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co2ta-c14)

Names (7): _corpus: _corpus:phase:co-ta:co2ta-c14  
_paper: _paper:10.1016/j.intermet.2014.01.015:λ1 (C14), paper:10.1016/j.jallcom.2022.166723:λ1  
_tdb: _tdb:CoTa-14Shi.tdb:CO2TA_C14, tdb:CoTa-19Wan.tdb:CO2TA_C14, tdb:CoTa-19Zho.tdb:CO2TA_C14, tdb:CoTa-22Wan.tdb:CO2TA_C14  


### TDB models of CO2TA_C14 (4): PHASE and CONSTITUENT statements as written

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): CO2TA_C14, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
58: PHASE CO2TA_C14 % 2 2 1  !
59: CONST CO2TA_C14 : CO% TA : CO TA% : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): CO2TA_C14, type code %A, sha256 `0188b050430162f4…`

~~~~text
59: PHASE CO2TA_C14 %A 3 2 1 3 !
60: CONST CO2TA_C14 : CO TA : CO TA : CO TA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): CO2TA_C14, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
63: PHASE CO2TA_C14 %A 2 2 1 !
64: CONST CO2TA_C14 : CO% TA : CO TA% : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): CO2TA_C14, type code %, sha256 `cab3db05a3994913…`

~~~~text
51: PHASE CO2TA_C14 % 2 2 1  !
52: CONST CO2TA_C14 : CO% TA : CO TA% : !
~~~~

Example references (4 of 4; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_

## CO2TA_C15 (Co–Ta)

- Id: `phase:co-ta:co2ta-c15`; status `assigned`
- Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type `st:c15-cu2mg-cf24`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-14Shi.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Zho.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-22Wan.tdb also describes the disordered state
- Stability: stable in 4 of 4 calculated diagram(s): 300–1923.45 K, x(Ta) 0.25891–0.3451
- Literature: 24 values (24 accepted) from 2 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co2ta-c15)

Names (7): _corpus: _corpus:phase:co-ta:co2ta-c15  
_paper: _paper:10.1016/j.intermet.2014.01.015:λ2 (C15), paper:10.1016/j.jallcom.2022.166723:λ2  
_tdb: _tdb:CoTa-14Shi.tdb:CO2TA_C15, tdb:CoTa-19Wan.tdb:CO2TA_C15, tdb:CoTa-19Zho.tdb:CO2TA_C15, tdb:CoTa-22Wan.tdb:CO2TA_C15  


### TDB models of CO2TA_C15 (4): PHASE and CONSTITUENT statements as written

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): CO2TA_C15, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
63: PHASE CO2TA_C15 % 2 2 1  !
64: CONST CO2TA_C15 : CO% TA : CO TA% : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): CO2TA_C15, type code %A, sha256 `0188b050430162f4…`

~~~~text
64: PHASE CO2TA_C15 %A 2 2 1 !
65: CONST CO2TA_C15 : CO% TA : CO TA% : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): CO2TA_C15, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
68: PHASE CO2TA_C15 %A 2 2 1 !
69: CONST CO2TA_C15 : CO% TA : CO TA% : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): CO2TA_C15, type code %, sha256 `cab3db05a3994913…`

~~~~text
56: PHASE CO2TA_C15 % 2 2 1  !
57: CONST CO2TA_C15 : CO% TA : CO TA% : !
~~~~

Example references (5 of 5; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1016/s0364-5916(00)00005-5](https://doi.org/10.1016/s0364-5916%2800%2900005-5) Zi-Kui Liu, Y.Austin Chang, Thermodynamic assessment of the Co-Ta system, Calphad 23, 339-356 (1999).  
_cited as the source of values for this phase_

## CO2TA_C36 (Co–Ta)

- Id: `phase:co-ta:co2ta-c36`; status `assigned`
- Structure: MgNi2 · C36 · hP24 · P6_3/mmc (194); type `st:c36-mgni2-hp24`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-14Shi.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Zho.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-22Wan.tdb also describes the disordered state
- Stability: stable in 4 of 4 calculated diagram(s): 1220.39–1850 K, x(Ta) 0.22511–0.2713
- Literature: 21 values (21 accepted) from 2 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co2ta-c36)

Names (7): _corpus: _corpus:phase:co-ta:co2ta-c36  
_paper: _paper:10.1016/j.intermet.2014.01.015:λ3 (C36), paper:10.1016/j.jallcom.2022.166723:λ3  
_tdb: _tdb:CoTa-14Shi.tdb:CO2TA_C36, tdb:CoTa-19Wan.tdb:CO2TA_C36, tdb:CoTa-19Zho.tdb:CO2TA_C36, tdb:CoTa-22Wan.tdb:CO2TA_C36  


### TDB models of CO2TA_C36 (4): PHASE and CONSTITUENT statements as written

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): CO2TA_C36, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
68: PHASE CO2TA_C36 % 2 2 1  !
69: CONST CO2TA_C36 : CO% TA : CO TA% : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): CO2TA_C36, type code %A, sha256 `0188b050430162f4…`

~~~~text
69: PHASE CO2TA_C36 %A 3 2 1 3 !
70: CONST CO2TA_C36 : CO TA : CO TA : CO TA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): CO2TA_C36, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
73: PHASE CO2TA_C36 %A 2 2 1 !
74: CONST CO2TA_C36 : CO% TA : CO TA% : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): CO2TA_C36, type code %, sha256 `cab3db05a3994913…`

~~~~text
61: PHASE CO2TA_C36 % 2 2 1  !
62: CONST CO2TA_C36 : CO% TA : CO TA% : !
~~~~

Example references (5 of 5; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1016/s0364-5916(00)00005-5](https://doi.org/10.1016/s0364-5916%2800%2900005-5) Zi-Kui Liu, Y.Austin Chang, Thermodynamic assessment of the Co-Ta system, Calphad 23, 339-356 (1999).  
_cited as the source of values for this phase_

## CO3TA (Co–Ta)

- Id: `phase:co-ta:co3ta`; status `assigned`
- Structure: BaPb3 · hR12 · R-3m (166); type `st:bapb3-hr12`; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
- Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) [doi:10.1016/j.calphad.2025.102833](https://doi.org/10.1016/j.calphad.2025.102833)
- Caveat: not certain from the name or DFT alone (no_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
- Stability: stable in 1 of 1 calculated diagram(s): 300–1320.39 K, x(Ta) 0.2363–0.25
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co3ta)

Names (2): _corpus: _corpus:phase:co-ta:co3ta  
_tdb: _tdb:CoTa-19Zho.tdb:CO3TA  


### TDB models of CO3TA (1): PHASE and CONSTITUENT statements as written

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): CO3TA, type code %, sha256 `f38abf64bd567e76…`

~~~~text
58: PHASE CO3TA % 2 3 1 !
59: CONST CO3TA : CO : CO TA% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase_

## CO3TA_C36 (Co–Ta)

- Id: `phase:co-ta:co3ta-c36`; status `needs_review`
- No structure assigned. Why: assessment_declared_blocked_by:stoichiometry_contradicts_C36; name_suggests_C36_but_dft_space_group_166; stoichiometry_contradicts_C36:CoTa-02Har.tdb
- Candidate (dft_mp): R-3m (166) — on-hull MP TaCo3 at x(TA)=0.2500
- Candidate (dft_oqmd): R-3m (166) — on-hull OQMD Co3 Ta1 at x(TA)=0.2500
- Candidate (name_token): MgNi2 · C36 · hP24 · P6_3/mmc (194) — Strukturbericht/word 'C36' in the TDB name
- Candidate (sgte_mmc2): MgNi2 · C36 · hP24 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CO3TA_C36: Co3Ta
- Candidate (tdb_comment): MgNi2 · hP24 · P6_3/mmc — CoTa-02Har.tdb: 'Prototype MgNi2 (hP24, P6_3/mmc)'
- Stoichiometry: Co 0.7500, Ta 0.2500
- Stability: stable in 1 of 1 calculated diagram(s): 300–1720.72 K, x(Ta) 0.25–0.25
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co3ta-c36)

Names (2): _corpus: _corpus:phase:co-ta:co3ta-c36  
_tdb: _tdb:CoTa-02Har.tdb:CO3TA_C36  


### TDB models of CO3TA_C36 (1): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): CO3TA_C36, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
49: PHASE CO3TA_C36 % 2 3 1  !
50: CONST CO3TA_C36 : CO : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## CO7TA2 (Co–Ta)

- Id: `phase:co-ta:co7ta2`; status `assigned`
- Structure: BaPb3 · hR12 · R-3m (166); type `st:bapb3-hr12`; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
- Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) [doi:10.1016/j.calphad.2025.102833](https://doi.org/10.1016/j.calphad.2025.102833)
- Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Co 0.7778, Ta 0.2222
- Stability: stable in 5 of 5 calculated diagram(s): 300–1316.43 K, x(Ta) 0.22222–0.22222
- Literature: 16 values (16 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:co7ta2)

Names (9): _corpus: _corpus:phase:co-ta:co7ta2  
_paper: _paper:10.1016/j.intermet.2014.01.015:Co7Ta2, paper:10.1016/j.jallcom.2022.166723:Co7Ta2, paper:10.1016/s0364-5916(00)00005-5:Co7Ta2  
_tdb: _tdb:CoTa-02Har.tdb:CO7TA2, tdb:CoTa-14Shi.tdb:CO7TA2, tdb:CoTa-19Wan.tdb:CO7TA2, tdb:CoTa-22Wan.tdb:CO7TA2, tdb:CoTa-99Liu-LB.tdb:CO7TA2  


### TDB models of CO7TA2 (5): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): CO7TA2, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
44: PHASE CO7TA2 % 2 7 2  !
45: CONST CO7TA2 : CO : TA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): CO7TA2, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
53: PHASE CO7TA2 % 2 7 2  !
54: CONST CO7TA2 : CO : TA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): CO7TA2, type code %, sha256 `0188b050430162f4…`

~~~~text
54: PHASE CO7TA2 % 2 7 2 !
55: CONST CO7TA2 : CO : TA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): CO7TA2, type code %, sha256 `cab3db05a3994913…`

~~~~text
46: PHASE CO7TA2 % 2 7 2  !
47: CONST CO7TA2 : CO : TA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): CO7TA2, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
40: PHASE CO7TA2 % 2 7 2  !
41: CONST CO7TA2 : CO : TA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_cited as the source of values for this phase_

## COTA2_C16 (Co–Ta)

- Id: `phase:co-ta:cota2-c16`; status `assigned`
- Structure: Al2Cu · C16 · tI12 · I4/mcm (140); type `st:c16-al2cu-ti12`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-14Shi.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Zho.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-22Wan.tdb also describes the disordered state
- Stability: stable in 6 of 6 calculated diagram(s): 300–2225.5 K, x(Ta) 0.62275–0.68661
- Literature: 19 values (19 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:cota2-c16)

Names (10): _corpus: _corpus:phase:co-ta:cota2-c16  
_paper: _paper:10.1016/j.intermet.2014.01.015:CoTa2, paper:10.1016/j.jallcom.2022.166723:CoTa2, paper:10.1016/s0364-5916(00)00005-5:CoTa2  
_tdb: _tdb:CoTa-02Har.tdb:COTA2_C16, tdb:CoTa-14Shi.tdb:COTA2_C16, tdb:CoTa-19Wan.tdb:COTA2_C16, tdb:CoTa-19Zho.tdb:COTA2_C16, tdb:CoTa-22Wan.tdb:COTA2_C16, tdb:CoTa-99Liu-LB.tdb:COTA2_C16  


### TDB models of COTA2_C16 (6): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): COTA2_C16, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
69: PHASE COTA2_C16 % 2 1 2  !
70: CONST COTA2_C16 : CO : TA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): COTA2_C16, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
78: PHASE COTA2_C16 % 2 1 2  !
79: CONST COTA2_C16 : CO% TA : CO TA% : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): COTA2_C16, type code %, sha256 `0188b050430162f4…`

~~~~text
84: PHASE COTA2_C16 % 2 1 2 !
85: CONST COTA2_C16 : CO% TA : CO TA% : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): COTA2_C16, type code %, sha256 `f38abf64bd567e76…`

~~~~text
83: PHASE COTA2_C16 % 2 1 2 !
84: CONST COTA2_C16 : CO% TA : CO TA% : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): COTA2_C16, type code %, sha256 `cab3db05a3994913…`

~~~~text
71: PHASE COTA2_C16 % 2 1 2  !
72: CONST COTA2_C16 : CO% TA : CO TA% : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): COTA2_C16, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
65: PHASE COTA2_C16 % 2 1 2  !
66: CONST COTA2_C16 : CO : TA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## MU_D85 (Co–Ta)

- Id: `phase:co-ta:d85-mu`; status `assigned`
- Structure: Fe7W6 · D8_5 · hR13 · R-3m (166); type `st:d8-5-fe7w6-hr13`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in CoTa-02Har.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-19Zho.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-22Wan.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in CoTa-99Liu-LB.tdb also describes the disordered state
- Stability: stable in 6 of 6 calculated diagram(s): 300–2045.23 K, x(Ta) 0.44838–0.55701
- Literature: 38 values (38 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:d85-mu)

Names (11): _corpus: _corpus:phase:co-ta:d85-mu, corpus:phase:co-ta:mu-d85  
_paper: _paper:10.1016/j.intermet.2014.01.015:μ, paper:10.1016/j.jallcom.2022.166723:μ, paper:10.1016/s0364-5916(00)00005-5:μ  
_tdb: _tdb:CoTa-02Har.tdb:MU_D85, tdb:CoTa-14Shi.tdb:MU_D85, tdb:CoTa-19Wan.tdb:MU_D85, tdb:CoTa-19Zho.tdb:MU_D85, tdb:CoTa-22Wan.tdb:MU_D85, tdb:CoTa-99Liu-LB.tdb:MU_D85  


### TDB models of MU_D85 (6): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): MU_D85, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
64: PHASE MU_D85 % 4 1 4 2 6 !
65: CONST MU_D85 : CO% TA : TA : CO TA% : CO : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): MU_D85, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
73: PHASE MU_D85 % 3 6 4 3 !
74: CONST MU_D85 : CO : TA : CO TA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): MU_D85, type code %AP, sha256 `0188b050430162f4…`

~~~~text
79: PHASE MU_D85 %AP 4 0.07692 0.30769 0.15385 0.46154 !
80: CONST MU_D85 : CO TA : CO TA : CO TA : CO TA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): MU_D85, type code %, sha256 `f38abf64bd567e76…`

~~~~text
78: PHASE MU_D85 % 4 1 4 2 6 !
79: CONST MU_D85 : CO TA : TA : CO TA : CO TA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): MU_D85, type code %, sha256 `cab3db05a3994913…`

~~~~text
66: PHASE MU_D85 % 4 1 4 2 6 !
67: CONST MU_D85 : TA : TA : CO TA : CO TA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): MU_D85, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
60: PHASE MU_D85 % 3 7 2 4 !
61: CONST MU_D85 : CO TA : TA : CO TA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## DIS_MU (Co–Ta)

- Id: `phase:co-ta:dis-mu`; status `needs_review`
- No structure assigned. Why: unrecognised_name_tokens:DIS
- Candidate (name_token): Fe7W6 · D8_5 · hR13 · R-3m (166) — Strukturbericht/word 'D85' in the TDB name
- Stability: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:dis-mu)

Names (2): _corpus: _corpus:phase:co-ta:dis-mu  
_tdb: _tdb:CoTa-19Wan.tdb:DIS_MU  


### TDB models of DIS_MU (1): PHASE and CONSTITUENT statements as written

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): DIS_MU, type code %A, sha256 `0188b050430162f4…`

~~~~text
74: PHASE DIS_MU %A 1 1 !
75: CONST DIS_MU : CO TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_

## FCC_4SL (Co–Ta)

- Id: `phase:co-ta:fcc-4sl`; status `needs_review`
- No structure assigned. Why: order_disorder_ambiguity:CoTa-19Wan.tdb_model_is_partitioned; order_disorder_ambiguity:CoTa-19Zho.tdb_model_is_partitioned; unrecognised_name_tokens:4SL
- Candidate (name_token): Cu · A1 · cF4 · Fm-3m (225) — Strukturbericht/word 'A1' in the TDB name
- Candidate (tdb_comment): AuCu3 · cP4 · Pm-3m — CoTa-19Wan.tdb: 'Prototype AuCu3 (cP4, Pm-3m)'
- Candidate (tdb_comment): AuCu3 · cP4 · Pm-3m — CoTa-19Zho.tdb: 'Prototype AuCu3 (cP4, Pm-3m)'
- Stability: stable in 2 of 2 calculated diagram(s): 691.7–1769.38 K, x(Ta) 0–0.05936
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:fcc-4sl)

Names (3): _corpus: _corpus:phase:co-ta:fcc-4sl  
_tdb: _tdb:CoTa-19Wan.tdb:FCC_4SL, tdb:CoTa-19Zho.tdb:FCC_4SL  


### TDB models of FCC_4SL (2): PHASE and CONSTITUENT statements as written

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): FCC_4SL, type code %AY, sha256 `0188b050430162f4…`

~~~~text
39: PHASE FCC_4SL:F %AY 5 0.25 0.25 0.25 0.25 1 !
40: CONST FCC_4SL:F : CO% TA : CO% TA : CO% TA : CO TA% : VA :  !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): FCC_4SL, type code %AY, sha256 `f38abf64bd567e76…`

~~~~text
43: PHASE FCC_4SL:F %AY 5 0.25 0.25 0.25 0.25 1 !
44: CONST FCC_4SL:F : CO% TA : CO% TA : CO% TA : CO TA% : VA :  !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase_

## FCC_A1 (Co–Ta)

- Id: `phase:co-ta:fcc-a1`; status `assigned`
- Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; tier A: standard phase name; confidence high
- Stability: stable in 6 of 6 calculated diagram(s): 621.48–1777.64 K, x(Ta) 0–0.05936
- Literature: 24 values (24 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:fcc-a1)

Names (13): _corpus: _corpus:phase:co-ta:fcc-a1  
_paper: _paper:10.1016/j.calphad.2018.12.002:FCC, paper:10.1016/j.jallcom.2022.166723:fcc, paper:10.1016/s0364-5916(00)00005-5:fcc  
_tdb: _tdb:CoTa-02Har.tdb:FCC_A1, tdb:CoTa-14Shi.tdb:A1_FCC, tdb:CoTa-14Shi.tdb:FCC_A1, tdb:CoTa-19Wan.tdb:A1_FCC, tdb:CoTa-19Wan.tdb:FCC_A1, tdb:CoTa-19Zho.tdb:A1_FCC, tdb:CoTa-19Zho.tdb:FCC_A1, tdb:CoTa-22Wan.tdb:FCC_A1, tdb:CoTa-99Liu-LB.tdb:FCC_A1  


### TDB models of FCC_A1 (9): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): FCC_A1, type code %A, sha256 `c7251b1bb94512ab…`

~~~~text
29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : CO% TA : VA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): A1_FCC, type code %A, sha256 `e4d873cf93726ad0…`

~~~~text
33: PHASE A1_FCC %A 2 1 1 !
34: CONST A1_FCC : CO% TA : VA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): FCC_A1, type code %A, sha256 `e4d873cf93726ad0…`

~~~~text
28: PHASE FCC_A1 %A 2 1 1 !
29: CONST FCC_A1 : CO% TA : VA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): A1_FCC, type code %A, sha256 `0188b050430162f4…`

~~~~text
34: PHASE A1_FCC %A 2 1 1 !
35: CONST A1_FCC : CO% TA : VA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): FCC_A1, type code %A, sha256 `0188b050430162f4…`

~~~~text
29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : CO% TA : VA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): A1_FCC, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
38: PHASE A1_FCC %A 2 1 1 !
39: CONST A1_FCC : CO% TA : VA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): FCC_A1, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
33: PHASE FCC_A1 %A 2 1 1 !
34: CONST FCC_A1 : CO% TA : VA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): FCC_A1, type code %A, sha256 `cab3db05a3994913…`

~~~~text
31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : CO% TA : VA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): FCC_A1, type code %A, sha256 `2d4f912a1ca1b737…`

~~~~text
25: PHASE FCC_A1 %A 2 1 1 !
26: CONST FCC_A1 : CO% TA : VA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## L12_FCC (Co–Ta)

- Id: `phase:co-ta:fcc-l12`; status `assigned`
- Structure: AuCu3 · L1_2 · cP4 · Pm-3m (221); type `st:l1-2-aucu3-cp4`; tier A: standard phase name; confidence high
- Caveat: CoTa-14Shi.tdb: ordered phase with disordered part A1_FCC (order/disorder model)
- Caveat: partitioned order/disorder model in CoTa-14Shi.tdb also describes the disordered state
- Stability: stable in 1 of 1 calculated diagram(s): 671.48–1773.65 K, x(Ta) 0–0.05927
- Literature: 10 values (10 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:fcc-l12)

Names (6): _corpus: _corpus:phase:co-ta:fcc-l12, corpus:phase:co-ta:l12-fcc  
_paper: _paper:10.1016/j.intermet.2014.01.015:γ, paper:10.1016/j.intermet.2014.01.015:γ (Co), paper:10.1016/j.intermet.2014.01.015:γ(Co)  
_tdb: _tdb:CoTa-14Shi.tdb:L12_FCC  


### TDB models of L12_FCC (1): PHASE and CONSTITUENT statements as written

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): L12_FCC, type code %AY, sha256 `e4d873cf93726ad0…`

~~~~text
38: PHASE L12_FCC %AY 3 0.75 0.25 1 !
39: CONST L12_FCC : CO% TA : CO TA% : VA :  !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; reports values for this phase_

## HCP_A3 (Co–Ta)

- Id: `phase:co-ta:hcp-a3`; status `assigned`
- Structure: Mg · A3 · hP2 · P6_3/mmc (194); type `st:a3-mg-hp2`; tier A: standard phase name; confidence high
- Stability: stable in 6 of 6 calculated diagram(s): 300–729.98 K, x(Ta) 0–0.01216
- Literature: 5 values (5 accepted) from 2 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:hcp-a3)

Names (9): _corpus: _corpus:phase:co-ta:hcp-a3  
_paper: _paper:10.1016/j.calphad.2018.12.002:HCP, paper:10.1016/s0364-5916(00)00005-5:hcp  
_tdb: _tdb:CoTa-02Har.tdb:HCP_A3, tdb:CoTa-14Shi.tdb:HCP_A3, tdb:CoTa-19Wan.tdb:HCP_A3, tdb:CoTa-19Zho.tdb:HCP_A3, tdb:CoTa-22Wan.tdb:HCP_A3, tdb:CoTa-99Liu-LB.tdb:HCP_A3  


### TDB models of HCP_A3 (6): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): HCP_A3, type code %A, sha256 `c7251b1bb94512ab…`

~~~~text
39: PHASE HCP_A3 %A 2 1 0.5 !
40: CONST HCP_A3 : CO% TA : VA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): HCP_A3, type code %A, sha256 `e4d873cf93726ad0…`

~~~~text
48: PHASE HCP_A3 %A 2 1 0.5 !
49: CONST HCP_A3 : CO% TA : VA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): HCP_A3, type code %A, sha256 `0188b050430162f4…`

~~~~text
49: PHASE HCP_A3 %A 2 1 0.5 !
50: CONST HCP_A3 : CO% TA : VA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): HCP_A3, type code %A, sha256 `f38abf64bd567e76…`

~~~~text
53: PHASE HCP_A3 %A 2 1 0.5 !
54: CONST HCP_A3 : CO% TA : VA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): HCP_A3, type code %A, sha256 `cab3db05a3994913…`

~~~~text
41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : CO% TA : VA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): HCP_A3, type code %A, sha256 `2d4f912a1ca1b737…`

~~~~text
35: PHASE HCP_A3 %A 2 1 0.5 !
36: CONST HCP_A3 : CO% TA : VA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase_
- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## LIQUID (Co–Ta)

- Id: `phase:co-ta:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 6 of 6 calculated diagram(s): 1552.64–4000 K, x(Ta) 0–1
- Literature: 54 values (54 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-ta:liquid)

Names (11): _corpus: _corpus:phase:co-ta:liquid  
_paper: _paper:10.1016/j.intermet.2014.01.015:liquid, paper:10.1016/j.jallcom.2022.166723:L, paper:10.1016/j.jallcom.2022.166723:Liquid, paper:10.1016/s0364-5916(00)00005-5:liquid  
_tdb: _tdb:CoTa-02Har.tdb:LIQUID, tdb:CoTa-14Shi.tdb:LIQUID, tdb:CoTa-19Wan.tdb:LIQUID, tdb:CoTa-19Zho.tdb:LIQUID, tdb:CoTa-22Wan.tdb:LIQUID, tdb:CoTa-99Liu-LB.tdb:LIQUID  


### TDB models of LIQUID (6): PHASE and CONSTITUENT statements as written

[CoTa-02Har.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-02Har.tdb): LIQUID, type code %, sha256 `c7251b1bb94512ab…`

~~~~text
24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : CO TA : !
~~~~

[CoTa-14Shi.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-14Shi.tdb): LIQUID, type code %, sha256 `e4d873cf93726ad0…`

~~~~text
23: PHASE LIQUID:L % 1 1 !
24: CONST LIQUID:L : CO TA : !
~~~~

[CoTa-19Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Wan.tdb): LIQUID, type code %, sha256 `0188b050430162f4…`

~~~~text
24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : CO TA : !
~~~~

[CoTa-19Zho.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-19Zho.tdb): LIQUID, type code %, sha256 `f38abf64bd567e76…`

~~~~text
28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : CO TA : !
~~~~

[CoTa-22Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-22Wan.tdb): LIQUID, type code %, sha256 `cab3db05a3994913…`

~~~~text
26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : CO TA : !
~~~~

[CoTa-99Liu-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/CoTa-99Liu-LB.tdb): LIQUID, type code %, sha256 `2d4f912a1ca1b737…`

~~~~text
20: PHASE LIQUID:L % 1 1 !
21: CONST LIQUID:L : CO TA : !
~~~~

Example references (6 of 6; assessments first): 

- [doi:10.1016/j.jallcom.2022.166723](https://doi.org/10.1016/j.jallcom.2022.166723) Cuiping Wang, Xiaodong Chen, Peng Yang, Qianqian Zhang, Shuiyuan Yang, Yong Lu et al., Experimental investigation and thermodynamic assessment of phase equilibria in the Al-Co-Ta ternary system, Journal of Alloys and Compounds 925, 166723 (2022).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/S0364-5916(00)00005-5](https://doi.org/10.1016/S0364-5916%2800%2900005-5) Z.-K. Liu, Y.A. Chang, Calphad, 23, 339-56(1999).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.intermet.2014.01.015](https://doi.org/10.1016/j.intermet.2014.01.015) Kazuya Shinagawa, Hibiki Chinen, Toshihiro Omori, Katsunari Oikawa, Ikuo Ohnuma, Kiyohito Ishida et al., Phase equilibria and thermodynamic calculation of the Co–Ta binary system, Intermetallics 49, 87-97 (2014).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2019.101649](https://doi.org/10.1016/j.calphad.2019.101649) C. Zhou, C. Guo, C. Li, Z. Du, Thermodynamic description of the Co–Ni–Ta system, Calphad 66 (2019) 101649, https://doi.org/10.1016/j.calphad.2019.101649 17  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2018.12.002](https://doi.org/10.1016/j.calphad.2018.12.002) Peisheng Wang, Jörg Koßmann, Ursula R. Kattner, Mauro Palumbo, Thomas Hammerschmidt, Gregory B. Olson, Thermodynamic assessment of the Co-Ta system, Calphad 64, 205-212 (2019).  
_assessment that models this phase_
- [doi:10.1515/ijmr-2002-0196](https://doi.org/10.1515/ijmr-2002-0196) K.C. Hari Kumar, T. Van Rompaey, P. Wollants, Z. Metallkd., 93, 1146-53(2002).  
_assessment that models this phase_

## Please cite

- R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735970
- R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23736065

Also cite B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file; A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work).

Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

```bibtex
@misc{orchid_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).