# Al–Nb phases

> Al–Nb system: 15 phases (tier A 8, liquid 1, needs_review 4, unresolved_no_candidates 2); 11 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/AL-NB.html · Markdown: https://data.orchid-project.org/phases/pages/AL-NB.md

15 phases (tier A 8, liquid 1, needs_review 4, unresolved_no_candidates 2); 11 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=AL-NB) · [full JSON](https://data.orchid-project.org/phases/systems/AL-NB.json) · [Al–Nb system page](https://data.orchid-project.org/systems/AL-NB.html) · [Markdown](https://data.orchid-project.org/phases/pages/AL-NB.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Al–Nb system (15)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [AL3NB_D022](#phase-al-nb-al3nb-d022); _phase:al-nb:al3nb-d022_ | Al3Ti · D0_22 · tI8 · I4/mmm (139) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–2000.79 K, x(Nb) 0.24856–0.25816 | 42 | 6 |
| [ALNB3_A15](#phase-al-nb-alnb3-a15); _phase:al-nb:alnb3-a15_ | Cr3Si · A15 · cP8 · Pm-3n (223) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–2335.05 K, x(Nb) 0.74601–0.84988 | 24 | 6 |
| [BCC_A2](#phase-al-nb-bcc-a2); _phase:al-nb: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(Nb) 0.31291–1 | 12 | 9 |
| [B2_BCC](#phase-al-nb-bcc-b2); _phase:al-nb:bcc-b2_ | CsCl · B2 · cP2 · Pm-3m (221) | tier A: standard phase name | stable in 3 of 3 calculated diagram(s): 300–3998.76 K, x(Nb) 0.52511–1 | 0 | 3 |
| [SIGMA_D8B](#phase-al-nb-d8b-sigma); _phase:al-nb:d8b-sigma_ | sigma-CrFe · D8_b · tP30 · P4_2/mnm (136) | tier A: standard phase name | stable in 5 of 5 calculated diagram(s): 300–2212.73 K, x(Nb) 0.52335–0.71072 | 24 | 5 |
| [SIGMA_DIS](#phase-al-nb-dis-sigma); _phase:al-nb:dis-sigma_ |  | needs_review | not stable in 1 calculated diagram(s) | 0 | 1 |
| [FCC_A1](#phase-al-nb-fcc-a1); _phase:al-nb:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 6 of 6 calculated diagram(s): 300–934.57 K, x(Nb) 0–0.00166 | 16 | 6 |
| [HCP_A3](#phase-al-nb-hcp-a3); _phase:al-nb:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 6 calculated diagram(s) | 0 | 6 |
| [LIQUID](#phase-al-nb-liquid); _phase:al-nb:liquid_ | liquid | liquid | stable in 6 of 6 calculated diagram(s): 927.57–4000 K, x(Nb) 0–1 | 69 | 6 |
| [SIGMA_OLD](#phase-al-nb-old-sigma); _phase:al-nb:old-sigma_ | sigma-CrFe · D8_b · tP30 · P4_2/mnm (136) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2237.63 K, x(Nb) 0.59625–0.72251 | 0 | 1 |
| [SIG2SL](#phase-al-nb-sig2sl); _phase:al-nb:sig2sl_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–2210 K, x(Nb) 0.55259–0.69154 | 0 | 1 |
| [SIG2SL3](#phase-al-nb-sig2sl3); _phase:al-nb:sig2sl3_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300.39–2210 K, x(Nb) 0.55259–0.69154 | 0 | 1 |
| [SIG2SL3X](#phase-al-nb-sig2sl3x); _phase:al-nb:sig2sl3x_ |  | unresolved_no_candidates | not stable in 1 calculated diagram(s) | 0 | 1 |
| [SIG2SL5](#phase-al-nb-sig2sl5); _phase:al-nb:sig2sl5_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300.39–2205.36 K, x(Nb) 0.55259–0.69154 | 0 | 1 |
| [SIG2SL5X](#phase-al-nb-sig2sl5x); _phase:al-nb:sig2sl5x_ |  | unresolved_no_candidates | not stable in 1 calculated diagram(s) | 0 | 1 |

## AL3NB_D022 (Al–Nb)

- Id: `phase:al-nb:al3nb-d022`; status `assigned`
- Structure: Al3Ti · D0_22 · tI8 · I4/mmm (139); type `st:d0-22-al3ti-ti8`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in AlNb-09Wit.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-15He.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-23Fio.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-97Ser-LB.tdb also describes the disordered state
- Stability: stable in 6 of 6 calculated diagram(s): 300–2000.79 K, x(Nb) 0.24856–0.25816
- Literature: 42 values (42 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:al3nb-d022)

Names (11): _corpus: _corpus:phase:al-nb:al3nb-d022  
_paper: _paper:10.1016/j.jallcom.2008.05.008:ε, paper:10.1016/j.jallcom.2015.02.182:NbAl3, paper:sha256-85fd53a1a176b694:Al3Nb\*  
_system_alias: _system_alias:al-nb:epsilon  
_tdb: _tdb:AlNb-08Zhu.tdb:AL3NB_D022, tdb:AlNb-09Wit.tdb:AL3NB_D022, tdb:AlNb-15He.tdb:AL3NB_D022, tdb:AlNb-23Fio.tdb:AL3NB_D022, tdb:AlNb-97Ser-LB.tdb:AL3NB_D022, tdb:AlNb-98Sau.tdb:AL3NB_D022  


### TDB models of AL3NB_D022 (6): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): AL3NB_D022, type code %, sha256 `a89bdff6737f8160…`

~~~~text
51: PHASE AL3NB_D022 % 2 3 1 !
52: CONST AL3NB_D022 : AL : NB : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): AL3NB_D022, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
57: PHASE AL3NB_D022 % 2 3 1 !
58: CONST AL3NB_D022 : AL% NB : AL NB% : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): AL3NB_D022, type code %, sha256 `d55f60a76b49353c…`

~~~~text
48: PHASE AL3NB_D022 % 2 3 1 !
49: CONST AL3NB_D022 : AL% NB : AL NB% : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): AL3NB_D022, type code %, sha256 `f8fec1a8af356181…`

~~~~text
53: PHASE AL3NB_D022 % 2 3 1 !
54: CONST AL3NB_D022 : AL% NB : AL NB% : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): AL3NB_D022, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
48: PHASE AL3NB_D022 % 2 3 1 !
49: CONST AL3NB_D022 : AL% NB : AL NB% : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): AL3NB_D022, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
57: PHASE AL3NB_D022 % 2 3 1 !
58: CONST AL3NB_D022 : AL : NB% : !
~~~~

Example references (9 of 9; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(80)90120-4](https://doi.org/10.1016/0022-5088%2880%2990120-4) J.L. Jorda, R. Flükiger, J. Muller, A New metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals 75, 227-239 (1980).  
_cited as the source of values for this phase_
- [doi:10.1016/j.jallcom.2014.02.045](https://doi.org/10.1016/j.jallcom.2014.02.045) F. Stein, C. He, I. Wossack, The liquidus surface of the Cr–Al–Nb system and re-investigation of the Cr–Nb and Al–Cr phase diagrams, Journal of Alloys and Compounds 598, 253-265 (2014).  
_cited as the source of values for this phase_
- [doi:10.1149/1.2124218](https://doi.org/10.1149/1.2124218) I. Shilo, H. F. Franzen, R. A. Schiffman, Enthalpies of Formation of Niobium Aluminides as Determined by the Knudsen Effusion Method, J. Electrochem. Soc. 129, 1608-1613 (1982).  
_cited as the source of values for this phase_

## ALNB3_A15 (Al–Nb)

- Id: `phase:al-nb:alnb3-a15`; status `assigned`
- Structure: Cr3Si · A15 · cP8 · Pm-3n (223); type `st:a15-cr3si-cp8`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in AlNb-09Wit.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-23Fio.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-97Ser-LB.tdb also describes the disordered state
- Stability: stable in 6 of 6 calculated diagram(s): 300–2335.05 K, x(Nb) 0.74601–0.84988
- Literature: 24 values (24 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:alnb3-a15)

Names (10): _corpus: _corpus:phase:al-nb:alnb3-a15  
_paper: _paper:10.1016/j.jallcom.2008.05.008:δ, paper:10.1016/j.jallcom.2015.02.182:Nb3Al, paper:sha256-85fd53a1a176b694:AlNb3\*\*  
_tdb: _tdb:AlNb-08Zhu.tdb:ALNB3_A15, tdb:AlNb-09Wit.tdb:ALNB3_A15, tdb:AlNb-15He.tdb:ALNB3_A15, tdb:AlNb-23Fio.tdb:ALNB3_A15, tdb:AlNb-97Ser-LB.tdb:ALNB3_A15, tdb:AlNb-98Sau.tdb:ALNB3_A15  


### TDB models of ALNB3_A15 (6): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): ALNB3_A15, type code %, sha256 `a89bdff6737f8160…`

~~~~text
61: PHASE ALNB3_A15 % 2 1 3 !
62: CONST ALNB3_A15 : AL NB : NB : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): ALNB3_A15, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
67: PHASE ALNB3_A15 % 2 1 3 !
68: CONST ALNB3_A15 : AL% NB : AL NB% : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): ALNB3_A15, type code %, sha256 `d55f60a76b49353c…`

~~~~text
58: PHASE ALNB3_A15 % 2 1 3 !
59: CONST ALNB3_A15 : AL% NB : NB : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): ALNB3_A15, type code %, sha256 `f8fec1a8af356181…`

~~~~text
58: PHASE ALNB3_A15 % 2 3 1 !
59: CONST ALNB3_A15 : AL NB% : AL% NB : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): ALNB3_A15, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
58: PHASE ALNB3_A15 % 2 1 3 !
59: CONST ALNB3_A15 : AL% NB : AL NB% : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): ALNB3_A15, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
67: PHASE ALNB3_A15 % 2 1 3 !
68: CONST ALNB3_A15 : AL% NB : NB : !
~~~~

Example references (7 of 7; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(80)90120-4](https://doi.org/10.1016/0022-5088%2880%2990120-4) J.L. Jorda, R. Flükiger, J. Muller, A New metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals 75, 227-239 (1980).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_

## BCC_A2 (Al–Nb)

- Id: `phase:al-nb: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(Nb) 0.31291–1
- Literature: 12 values (12 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:bcc-a2)

Names (14): _corpus: _corpus:phase:al-nb:bcc-a2  
_paper: _paper:10.1016/j.jallcom.2008.05.008:β, paper:10.1016/j.jallcom.2015.02.182:(Nb), paper:sha256-85fd53a1a176b694:bcc-A2  
_system_alias: _system_alias:al-nb:beta  
_tdb: _tdb:AlNb-08Zhu.tdb:A2_BCC, tdb:AlNb-08Zhu.tdb:BCC_A2, tdb:AlNb-09Wit.tdb:A2_BCC, tdb:AlNb-09Wit.tdb:BCC_A2, tdb:AlNb-15He.tdb:BCC_A2, tdb:AlNb-23Fio.tdb:BCC_A2, tdb:AlNb-97Ser-LB.tdb:BCC_A2, tdb:AlNb-98Sau.tdb:A2_BCC, tdb:AlNb-98Sau.tdb:BCC_A2  


### TDB models of BCC_A2 (9): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): A2_BCC, type code %, sha256 `a89bdff6737f8160…`

~~~~text
36: PHASE A2_BCC % 2 1 3 !
37: CONST A2_BCC : AL NB VA : VA : !
~~~~

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): BCC_A2, type code %, sha256 `a89bdff6737f8160…`

~~~~text
31: PHASE BCC_A2 % 2 1 3 !
32: CONST BCC_A2 : AL NB : VA : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): A2_BCC, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
42: PHASE A2_BCC % 2 1 3 !
43: CONST A2_BCC : AL NB : VA : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): BCC_A2, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
37: PHASE BCC_A2 % 2 1 3 !
38: CONST BCC_A2 : AL NB : VA : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): BCC_A2, type code %B, sha256 `d55f60a76b49353c…`

~~~~text
38: PHASE BCC_A2 %B 2 1 3 !
39: CONST BCC_A2 : AL NB : VA : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): BCC_A2, type code %, sha256 `f8fec1a8af356181…`

~~~~text
43: PHASE BCC_A2 % 2 1 3 !
44: CONST BCC_A2 : AL NB : VA : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): BCC_A2, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
38: PHASE BCC_A2 % 2 1 3 !
39: CONST BCC_A2 : AL NB : VA : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): A2_BCC, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
42: PHASE A2_BCC % 2 1 3 !
43: CONST A2_BCC : AL NB VA : VA : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): BCC_A2, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
37: PHASE BCC_A2 % 2 1 3 !
38: CONST BCC_A2 : AL NB : VA : !
~~~~

Example references (7 of 7; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(80)90120-4](https://doi.org/10.1016/0022-5088%2880%2990120-4) J.L. Jorda, R. Flükiger, J. Muller, A New metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals 75, 227-239 (1980).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_

## B2_BCC (Al–Nb)

- Id: `phase:al-nb:bcc-b2`; status `assigned`
- Structure: CsCl · B2 · cP2 · Pm-3m (221); type `st:b2-cscl-cp2`; tier A: standard phase name; confidence high
- Caveat: AlNb-08Zhu.tdb: ordered phase with disordered part A2_BCC (order/disorder model)
- Caveat: AlNb-09Wit.tdb: ordered phase with disordered part A2_BCC (order/disorder model)
- Caveat: AlNb-98Sau.tdb: ordered phase with disordered part A2_BCC (order/disorder model)
- Caveat: partitioned order/disorder model in AlNb-08Zhu.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-09Wit.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-98Sau.tdb also describes the disordered state
- Stability: stable in 3 of 3 calculated diagram(s): 300–3998.76 K, x(Nb) 0.52511–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:bcc-b2)

Names (4): _corpus: _corpus:phase:al-nb:bcc-b2  
_tdb: _tdb:AlNb-08Zhu.tdb:B2_BCC, tdb:AlNb-09Wit.tdb:B2_BCC, tdb:AlNb-98Sau.tdb:B2_BCC  


### TDB models of B2_BCC (3): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): B2_BCC, type code %O, sha256 `a89bdff6737f8160…`

~~~~text
41: PHASE B2_BCC %O 3 0.5 0.5 3 !
42: CONST B2_BCC : AL% NB VA : AL NB% VA : VA : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): B2_BCC, type code %O, sha256 `4dcb4c37be340bee…`

~~~~text
47: PHASE B2_BCC %O 3 0.5 0.5 3 !
48: CONST B2_BCC : AL% NB : AL NB% : VA : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): B2_BCC, type code %O, sha256 `62c0666d7a7aae9c…`

~~~~text
47: PHASE B2_BCC %O 3 0.5 0.5 3 !
48: CONST B2_BCC : AL% NB VA : AL NB% VA : VA : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase_
- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase_

## SIGMA_D8B (Al–Nb)

- Id: `phase:al-nb:d8b-sigma`; status `assigned`
- Structure: sigma-CrFe · D8_b · tP30 · P4_2/mnm (136); type `st:d8-b-sigma-crfe-tp30`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in AlNb-08Zhu.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-09Wit.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-15He.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-23Fio.tdb also describes the disordered state
- Caveat: partitioned order/disorder model in AlNb-97Ser-LB.tdb also describes the disordered state
- Stability: stable in 5 of 5 calculated diagram(s): 300–2212.73 K, x(Nb) 0.52335–0.71072
- Literature: 24 values (24 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:d8b-sigma)

Names (10): _corpus: _corpus:phase:al-nb:d8b-sigma, corpus:phase:al-nb:sigma-d8b  
_paper: _paper:10.1016/j.jallcom.2008.05.008:σ, paper:10.1016/j.jallcom.2015.02.182:Nb2Al, paper:sha256-85fd53a1a176b694:σ  
_tdb: _tdb:AlNb-08Zhu.tdb:SIGMA_D8B, tdb:AlNb-09Wit.tdb:SIGMA_D8B, tdb:AlNb-15He.tdb:SIGMA_D8B, tdb:AlNb-23Fio.tdb:SIGMA_D8B, tdb:AlNb-97Ser-LB.tdb:SIGMA_D8B  


### TDB models of SIGMA_D8B (5): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): SIGMA_D8B, type code %, sha256 `a89bdff6737f8160…`

~~~~text
56: PHASE SIGMA_D8B % 3 10 4 16 !
57: CONST SIGMA_D8B : AL NB : NB : AL NB : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): SIGMA_D8B, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
62: PHASE SIGMA_D8B % 3 10 4 16 !
63: CONST SIGMA_D8B : AL NB : NB : AL NB : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): SIGMA_D8B, type code %, sha256 `d55f60a76b49353c…`

~~~~text
53: PHASE SIGMA_D8B % 3 10 4 16 !
54: CONST SIGMA_D8B : AL NB : NB : AL NB : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIGMA_D8B, type code %S, sha256 `f8fec1a8af356181…`

~~~~text
68: PHASE SIGMA_D8B %S 5 2 4 8 8 8 !
69: CONST SIGMA_D8B : AL NB : AL NB : AL NB : AL NB : AL NB : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): SIGMA_D8B, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
53: PHASE SIGMA_D8B % 3 10 4 16 !
54: CONST SIGMA_D8B : AL NB : NB : AL NB : !
~~~~

Example references (7 of 7; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(80)90120-4](https://doi.org/10.1016/0022-5088%2880%2990120-4) J.L. Jorda, R. Flükiger, J. Muller, A New metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals 75, 227-239 (1980).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_

## SIGMA_DIS (Al–Nb)

- Id: `phase:al-nb:dis-sigma`; status `needs_review`
- No structure assigned. Why: unrecognised_name_tokens:DIS
- Candidate (name_token): sigma-CrFe · D8_b · tP30 · P4_2/mnm (136) — Strukturbericht/word 'D8B' 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:al-nb:dis-sigma)

Names (2): _corpus: _corpus:phase:al-nb:dis-sigma  
_tdb: _tdb:AlNb-23Fio.tdb:SIGMA_DIS  


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

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIGMA_DIS, type code %, sha256 `f8fec1a8af356181…`

~~~~text
63: PHASE SIGMA_DIS % 1 1 !
64: CONST SIGMA_DIS : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_

## FCC_A1 (Al–Nb)

- Id: `phase:al-nb: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): 300–934.57 K, x(Nb) 0–0.00166
- Literature: 16 values (16 accepted) from 3 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:fcc-a1)

Names (10): _corpus: _corpus:phase:al-nb:fcc-a1  
_paper: _paper:10.1016/j.jallcom.2008.05.008:(αAl), paper:10.1016/j.jallcom.2015.02.182:(Al), paper:sha256-85fd53a1a176b694:fcc-Al  
_tdb: _tdb:AlNb-08Zhu.tdb:FCC_A1, tdb:AlNb-09Wit.tdb:FCC_A1, tdb:AlNb-15He.tdb:FCC_A1, tdb:AlNb-23Fio.tdb:FCC_A1, tdb:AlNb-97Ser-LB.tdb:FCC_A1, tdb:AlNb-98Sau.tdb:FCC_A1  


### TDB models of FCC_A1 (6): PHASE and CONSTITUENT statements as written

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): FCC_A1, type code %, sha256 `a89bdff6737f8160…`

~~~~text
26: PHASE FCC_A1 % 2 1 1 !
27: CONST FCC_A1 : AL NB : VA : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): FCC_A1, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
32: PHASE FCC_A1 % 2 1 1 !
33: CONST FCC_A1 : AL NB : VA : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): FCC_A1, type code %A, sha256 `d55f60a76b49353c…`

~~~~text
33: PHASE FCC_A1 %A 2 1 1 !
34: CONST FCC_A1 : AL NB : VA : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): FCC_A1, type code %, sha256 `f8fec1a8af356181…`

~~~~text
38: PHASE FCC_A1 % 2 1 1 !
39: CONST FCC_A1 : AL NB : VA : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): FCC_A1, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
33: PHASE FCC_A1 % 2 1 1 !
34: CONST FCC_A1 : AL NB : VA : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): FCC_A1, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
32: PHASE FCC_A1 % 2 1 1 !
33: CONST FCC_A1 : AL NB : VA : !
~~~~

Example references (7 of 7; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_
- [doi:10.1149/1.2124218](https://doi.org/10.1149/1.2124218) I. Shilo, H. F. Franzen, R. A. Schiffman, Enthalpies of Formation of Niobium Aluminides as Determined by the Knudsen Effusion Method, J. Electrochem. Soc. 129, 1608-1613 (1982).  
_cited as the source of values for this phase_

## HCP_A3 (Al–Nb)

- Id: `phase:al-nb: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: not stable in 6 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:hcp-a3)

Names (7): _corpus: _corpus:phase:al-nb:hcp-a3  
_tdb: _tdb:AlNb-08Zhu.tdb:HCP_A3, tdb:AlNb-09Wit.tdb:HCP_A3, tdb:AlNb-15He.tdb:HCP_A3, tdb:AlNb-23Fio.tdb:HCP_A3, tdb:AlNb-97Ser-LB.tdb:HCP_A3, tdb:AlNb-98Sau.tdb:HCP_A3  


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

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): HCP_A3, type code %, sha256 `a89bdff6737f8160…`

~~~~text
46: PHASE HCP_A3 % 2 1 0.5 !
47: CONST HCP_A3 : AL NB : VA : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): HCP_A3, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
52: PHASE HCP_A3 % 2 1 0.5 !
53: CONST HCP_A3 : AL NB : VA : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): HCP_A3, type code %A, sha256 `d55f60a76b49353c…`

~~~~text
43: PHASE HCP_A3 %A 2 1 0.5 !
44: CONST HCP_A3 : AL NB : VA : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): HCP_A3, type code %, sha256 `f8fec1a8af356181…`

~~~~text
48: PHASE HCP_A3 % 2 1 0.5 !
49: CONST HCP_A3 : AL NB : VA : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): HCP_A3, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
43: PHASE HCP_A3 % 2 1 0.5 !
44: CONST HCP_A3 : AL NB : VA : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): HCP_A3, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
52: PHASE HCP_A3 % 2 1 0.5 !
53: CONST HCP_A3 : AL NB : VA : !
~~~~

Example references (4 of 4; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase_
- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase_

## LIQUID (Al–Nb)

- Id: `phase:al-nb:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 6 of 6 calculated diagram(s): 927.57–4000 K, x(Nb) 0–1
- Literature: 69 values (69 accepted) from 4 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:liquid)

Names (12): _corpus: _corpus:phase:al-nb:liquid  
_paper: _paper:10.1016/j.jallcom.2007.06.033:liquid, paper:10.1016/j.jallcom.2008.05.008:L, paper:10.1016/j.jallcom.2015.02.182:L, paper:10.1016/j.jallcom.2015.02.182:liquid, paper:sha256-85fd53a1a176b694:Liquid  
_tdb: _tdb:AlNb-08Zhu.tdb:LIQUID, tdb:AlNb-09Wit.tdb:LIQUID, tdb:AlNb-15He.tdb:LIQUID, tdb:AlNb-23Fio.tdb:LIQUID, tdb:AlNb-97Ser-LB.tdb:LIQUID, tdb:AlNb-98Sau.tdb:LIQUID  


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

[AlNb-08Zhu.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-08Zhu.tdb): LIQUID, type code %, sha256 `a89bdff6737f8160…`

~~~~text
21: PHASE LIQUID:L % 1 1 !
22: CONST LIQUID:L : AL NB : !
~~~~

[AlNb-09Wit.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-09Wit.tdb): LIQUID, type code %, sha256 `4dcb4c37be340bee…`

~~~~text
27: PHASE LIQUID:L % 1 1 !
28: CONST LIQUID:L : AL NB : !
~~~~

[AlNb-15He.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-15He.tdb): LIQUID, type code %, sha256 `d55f60a76b49353c…`

~~~~text
28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : AL NB : !
~~~~

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): LIQUID, type code %, sha256 `f8fec1a8af356181…`

~~~~text
33: PHASE LIQUID:L % 1 1 !
34: CONST LIQUID:L : AL NB : !
~~~~

[AlNb-97Ser-LB.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-97Ser-LB.tdb): LIQUID, type code %, sha256 `b55876dc0b3e6a6b…`

~~~~text
28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : AL NB : !
~~~~

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): LIQUID, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
27: PHASE LIQUID:L % 1 1 !
28: CONST LIQUID:L : AL NB : !
~~~~

Example references (9 of 9; assessments first): 

- [doi:10.1016/j.jallcom.2008.05.008](https://doi.org/10.1016/j.jallcom.2008.05.008) V.T. Witusiewicz, A.A. Bondar, U. Hecht, T.Ya. Velikanova, The Al–B–Nb–Ti system, Journal of Alloys and Compounds 472, 133-161 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2015.02.182](https://doi.org/10.1016/j.jallcom.2015.02.182) Cuiyun He, Frank Stein, Martin Palm, Thermodynamic description of the systems Co–Nb, Al–Nb and Co–Al–Nb, Journal of Alloys and Compounds 637, 361-375 (2015).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/j.jallcom.2007.06.033](https://doi.org/10.1016/j.jallcom.2007.06.033) Zhijun Zhu, Yong Du, Lijun Zhang, Hailin Chen, Honghui Xu, Chengying Tang, Experimental identification of the degenerated equilibrium and thermodynamic modeling in the Al–Nb system, Journal of Alloys and Compounds 460, 632-638 (2008).  
_assessment that models this phase; cited as the source of values for this phase; reports values for this phase_
- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_
- [doi:10.1002/bbpc.19981020923](https://doi.org/10.1002/bbpc.19981020923) C. Servant, I. Ansara, Thermodynamic assessment of the Al‐Nb‐Ti system, Ber Bunsenges Phys Chem 102, 1189-1205 (1998).  
_cited as the source of values for this phase_
- [doi:10.1051/jcp/1997940869](https://doi.org/10.1051/jcp/1997940869) C Servant, I Ansara, Thermodynamic assessment of the Al-Nb system, J. Chim. Phys. 94, 869-888 (1997).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(80)90120-4](https://doi.org/10.1016/0022-5088%2880%2990120-4) J.L. Jorda, R. Flükiger, J. Muller, A New metallurgical investigation of the niobium-aluminium system, Journal of the Less Common Metals 75, 227-239 (1980).  
_cited as the source of values for this phase_
- [doi:10.1016/j.jallcom.2014.02.045](https://doi.org/10.1016/j.jallcom.2014.02.045) F. Stein, C. He, I. Wossack, The liquidus surface of the Cr–Al–Nb system and re-investigation of the Cr–Nb and Al–Cr phase diagrams, Journal of Alloys and Compounds 598, 253-265 (2014).  
_cited as the source of values for this phase_
- [doi:10.1149/1.2124218](https://doi.org/10.1149/1.2124218) I. Shilo, H. F. Franzen, R. A. Schiffman, Enthalpies of Formation of Niobium Aluminides as Determined by the Knudsen Effusion Method, J. Electrochem. Soc. 129, 1608-1613 (1982).  
_cited as the source of values for this phase_

## SIGMA_OLD (Al–Nb)

- Id: `phase:al-nb:old-sigma`; status `assigned`
- Structure: sigma-CrFe · D8_b · tP30 · P4_2/mnm (136); type `st:d8-b-sigma-crfe-tp30`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–2237.63 K, x(Nb) 0.59625–0.72251
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:old-sigma)

Names (3): _corpus: _corpus:phase:al-nb:old-sigma, corpus:phase:al-nb:sigma-old  
_tdb: _tdb:AlNb-98Sau.tdb:SIGMA_OLD  


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

[AlNb-98Sau.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-98Sau.tdb): SIGMA_OLD, type code %, sha256 `62c0666d7a7aae9c…`

~~~~text
62: PHASE SIGMA_OLD % 3 8 4 18 !
63: CONST SIGMA_OLD : AL : NB : AL NB : !
~~~~

## SIG2SL (Al–Nb)

- Id: `phase:al-nb:sig2sl`; status `needs_review`
- No structure assigned. Why: name_has_descriptive_tokens:SIG2SL; no_structure_token
- Candidate (dft_mp): P4_2/mnm (136) — on-hull MP Nb2Al at x(NB)=0.6667
- Candidate (dft_oqmd): P42/mnm (136) — on-hull OQMD Al1 Nb2 at x(NB)=0.6667
- Stability: stable in 1 of 1 calculated diagram(s): 300–2210 K, x(Nb) 0.55259–0.69154
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:sig2sl)

Names (2): _corpus: _corpus:phase:al-nb:sig2sl  
_tdb: _tdb:AlNb-23Fio.tdb:SIG2SL  


### TDB models of SIG2SL (1): PHASE and CONSTITUENT statements as written

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIG2SL, type code %, sha256 `f8fec1a8af356181…`

~~~~text
73: PHASE SIG2SL % 2 20 10 !
74: CONST SIG2SL : AL NB : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_

## SIG2SL3 (Al–Nb)

- Id: `phase:al-nb:sig2sl3`; status `needs_review`
- No structure assigned. Why: name_has_descriptive_tokens:SIG2SL3; no_structure_token
- Candidate (dft_mp): P4_2/mnm (136) — on-hull MP Nb2Al at x(NB)=0.6667
- Candidate (dft_oqmd): P42/mnm (136) — on-hull OQMD Al1 Nb2 at x(NB)=0.6667
- Stability: stable in 1 of 1 calculated diagram(s): 300.39–2210 K, x(Nb) 0.55259–0.69154
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:sig2sl3)

Names (2): _corpus: _corpus:phase:al-nb:sig2sl3  
_tdb: _tdb:AlNb-23Fio.tdb:SIG2SL3  


### TDB models of SIG2SL3 (1): PHASE and CONSTITUENT statements as written

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIG2SL3, type code %T, sha256 `f8fec1a8af356181…`

~~~~text
83: PHASE SIG2SL3 %T 3 4 16 10 !
84: CONST SIG2SL3 : AL NB : AL NB : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_

## SIG2SL3X (Al–Nb)

- Id: `phase:al-nb:sig2sl3x`; status `unresolved_no_candidates`
- No structure assigned. Why: name_has_descriptive_tokens:SIG2SL3X; no_structure_token
- 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:al-nb:sig2sl3x)

Names (2): _corpus: _corpus:phase:al-nb:sig2sl3x  
_tdb: _tdb:AlNb-23Fio.tdb:SIG2SL3X  


### TDB models of SIG2SL3X (1): PHASE and CONSTITUENT statements as written

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIG2SL3X, type code %, sha256 `f8fec1a8af356181…`

~~~~text
78: PHASE SIG2SL3X % 1 1 !
79: CONST SIG2SL3X : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_

## SIG2SL5 (Al–Nb)

- Id: `phase:al-nb:sig2sl5`; status `needs_review`
- No structure assigned. Why: name_has_descriptive_tokens:SIG2SL5; no_structure_token
- Candidate (dft_mp): P4_2/mnm (136) — on-hull MP Nb2Al at x(NB)=0.6667
- Candidate (dft_oqmd): P42/mnm (136) — on-hull OQMD Al1 Nb2 at x(NB)=0.6667
- Stability: stable in 1 of 1 calculated diagram(s): 300.39–2205.36 K, x(Nb) 0.55259–0.69154
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:al-nb:sig2sl5)

Names (2): _corpus: _corpus:phase:al-nb:sig2sl5  
_tdb: _tdb:AlNb-23Fio.tdb:SIG2SL5  


### TDB models of SIG2SL5 (1): PHASE and CONSTITUENT statements as written

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIG2SL5, type code %U, sha256 `f8fec1a8af356181…`

~~~~text
93: PHASE SIG2SL5 %U 5 2 4 8 8 8 !
94: CONST SIG2SL5 : AL NB : AL NB : AL NB : AL NB : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_assessment that models this phase_

## SIG2SL5X (Al–Nb)

- Id: `phase:al-nb:sig2sl5x`; status `unresolved_no_candidates`
- No structure assigned. Why: name_has_descriptive_tokens:SIG2SL5X; no_structure_token
- 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:al-nb:sig2sl5x)

Names (2): _corpus: _corpus:phase:al-nb:sig2sl5x  
_tdb: _tdb:AlNb-23Fio.tdb:SIG2SL5X  


### TDB models of SIG2SL5X (1): PHASE and CONSTITUENT statements as written

[AlNb-23Fio.tdb](https://orchid-project.org/data/databases/sgte-binary/AlNb-23Fio.tdb): SIG2SL5X, type code %, sha256 `f8fec1a8af356181…`

~~~~text
88: PHASE SIG2SL5X % 1 1 !
89: CONST SIG2SL5X : AL NB : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2022.102522](https://doi.org/10.1016/j.calphad.2022.102522) J.M. Fiorani, M. Badran, J.M. Joubert, J.C. Crivello, A.A.A.P. da Silva, G.C. Coelho et al., New approach to the compound energy formalism (NACEF) Part II. Thermodynamic modelling of the Al–Nb system supported by first-principles calculations, Calphad 80, 102522 (2023).  
_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).