Co–Dy phases

11 phases (tier A 6, tier C 3, liquid 1, needs_review 1); 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 · full JSON · Co–Dy system page · Markdown · field reference

Phases of the Co–Dy system (11)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:co-dy:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 1654.26–2499.96 K, x(Dy) 0.99965–1	2
CO17DY2 phase:co-dy:co17dy2		needs_review	stable in 2 of 2 calculated diagram(s): 300–1661.95 K, x(Dy) 0.10526–0.16002	2
CO2DY_C15 phase:co-dy:co2dy-c15	Cu2Mg · C15 · cF24 · Fd-3m (227)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1552.42 K, x(Dy) 0.33333–0.33333	2
CO3DY phase:co-dy:co3dy	Ni3Pu · hR12 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1623.82 K, x(Dy) 0.25–0.25	2
CO5DY_D2D phase:co-dy:co5dy-d2d	CaCu5 · D2_d · hP6 · P6/mmm (191)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1404.85–1616.18 K, x(Dy) 0.16667–0.16667	1
CO7DY12 phase:co-dy:co7dy12	Co7Ho12 · mP38 · P2_1/c (14)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1031.58 K, x(Dy) 0.63158–0.63158	2
CO7DY2 phase:co-dy:co7dy2	Co7Gd2 · hR18 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1615.53 K, x(Dy) 0.22222–0.22222	2
CODY3_D011 phase:co-dy:cody3-d011	Fe3C · D0_11 · oP16 · Pnma (62)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1143.89 K, x(Dy) 0.75–0.75	2
FCC_A1 phase:co-dy:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 632.49–1773.89 K, x(Dy) 0–0.00174	2
HCP_A3 phase:co-dy:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1689.99 K, x(Dy) 0–1	2
LIQUID phase:co-dy:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 993.35–2500 K, x(Dy) 0–1	2

BCC_A2 (Co–Dy)

Id: phase:co-dy: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 2 of 2 calculated diagram(s): 1654.26–2499.96 K, x(Dy) 0.99965–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:bcc-a2
tdb: tdb:CoDy-96Su.tdb:BCC_A2, tdb:CoDy-98Su.tdb:BCC_A2

TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: BCC_A2, type code %B, sha256 6bdfab6e817c7d70…

39: PHASE BCC_A2 %B 2 1 3 !
40: CONST BCC_A2 : CO DY : VA : !

CoDy-98Su.tdb: BCC_A2, type code %B, sha256 ef3d3e66257222b3…

47: PHASE BCC_A2 %B 2 1 3 !
48: CONST BCC_A2 : CO DY : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CO17DY2 (Co–Dy)

Id: phase:co-dy:co17dy2; status needs_review
No structure assigned. Why: no_structure_token; off_stoichiometric_model; sgte_mmc2_rows_disagree
Candidate (dft_mp): R-3m (166) — on-hull MP Dy2Co17 at x(DY)=0.1053
Candidate (dft_oqmd): P63/mmc (194) — on-hull OQMD Co17 Dy2 at x(DY)=0.1053
Candidate (sgte_mmc2): CaCu5 · D2_d · hP6 · P6/mmm (191) — Hallstedt 2025 mmc2 row for CO17DY2: Co5Dy
Candidate (sgte_mmc2): Th2Zn17 · hR19 · R-3m (166) — Hallstedt 2025 mmc2 row for CO17DY2: Co17Dy2
Candidate (tdb_comment): Th2Zn17 · hR19 · R-3m — CoDy-96Su.tdb: 'Prototype Th2Zn17 (hR19, R-3m)'
Candidate (tdb_comment): Th2Zn17 · hR19 · R-3m — CoDy-98Su.tdb: 'Prototype Th2Zn17 (hR19, R-3m) and CaCu5 (hP6, P6/mmm)'
Stability: stable in 2 of 2 calculated diagram(s): 300–1661.95 K, x(Dy) 0.10526–0.16002
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:co17dy2
tdb: tdb:CoDy-96Su.tdb:CO17DY2, tdb:CoDy-98Su.tdb:CO17DY2

TDB models of CO17DY2 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO17DY2, type code %A, sha256 6bdfab6e817c7d70…

49: PHASE CO17DY2 %A 2 17 2 !
50: CONST CO17DY2 : CO : DY : !

CoDy-98Su.tdb: CO17DY2, type code %A, sha256 ef3d3e66257222b3…

58: PHASE CO17DY2 %A 3 15 1 2 !
59: CONST CO17DY2 : CO : CO2 DY : CO2 DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CO2DY_C15 (Co–Dy)

Id: phase:co-dy:co2dy-c15; status assigned
Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type st:c15-cu2mg-cf24; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaaadxc and oqmd-20722, space group 227
Stoichiometry: Co 0.6667, Dy 0.3333
Stability: stable in 2 of 2 calculated diagram(s): 300–1552.42 K, x(Dy) 0.33333–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:co-dy:co2dy-c15
mp: mp:mp-aaaaadxc
oqmd: oqmd:oqmd-20722
tdb: tdb:CoDy-96Su.tdb:CO2DY_C15, tdb:CoDy-98Su.tdb:CO2DY_C15

TDB models of CO2DY_C15 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO2DY_C15, type code %A, sha256 6bdfab6e817c7d70…

69: PHASE CO2DY_C15 %A 2 2 1 !
70: CONST CO2DY_C15 : CO : DY : !

CoDy-98Su.tdb: CO2DY_C15, type code %A, sha256 ef3d3e66257222b3…

73: PHASE CO2DY_C15 %A 2 2 1 !
74: CONST CO2DY_C15 : CO : DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CO3DY (Co–Dy)

Id: phase:co-dy:co3dy; status assigned
Structure: Ni3Pu · hR12 · R-3m (166); type st:ni3pu-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
Caveat: not certain from the name or DFT alone (dft_space_group_166_matches_2_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Co 0.7500, Dy 0.2500
Stability: stable in 2 of 2 calculated diagram(s): 300–1623.82 K, x(Dy) 0.25–0.25
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:co3dy
tdb: tdb:CoDy-96Su.tdb:CO3DY, tdb:CoDy-98Su.tdb:CO3DY

TDB models of CO3DY (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO3DY, type code %A, sha256 6bdfab6e817c7d70…

64: PHASE CO3DY %A 2 3 1 !
65: CONST CO3DY : CO : DY : !

CoDy-98Su.tdb: CO3DY, type code %A, sha256 ef3d3e66257222b3…

68: PHASE CO3DY %A 2 3 1 !
69: CONST CO3DY : CO : DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CO5DY_D2D (Co–Dy)

Id: phase:co-dy:co5dy-d2d; status assigned
Structure: CaCu5 · D2_d · hP6 · P6/mmm (191); type st:d2-d-cacu5-hp6; tier A: standard phase name; confidence high
Stoichiometry: Co 0.8333, Dy 0.1667
Stability: stable in 1 of 1 calculated diagram(s): 1404.85–1616.18 K, x(Dy) 0.16667–0.16667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:co-dy:co5dy-d2d
tdb: tdb:CoDy-96Su.tdb:CO5DY_D2D

TDB models of CO5DY_D2D (1): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO5DY_D2D, type code %A, sha256 6bdfab6e817c7d70…

54: PHASE CO5DY_D2D %A 2 5 1 !
55: CONST CO5DY_D2D : CO : DY : !

CO7DY12 (Co–Dy)

Id: phase:co-dy:co7dy12; status assigned
Structure: Co7Ho12 · mP38 · P2_1/c (14); type st:co7ho12-mp38; 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
Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_oqmd, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Co 0.3684, Dy 0.6316
Stability: stable in 2 of 2 calculated diagram(s): 300–1031.58 K, x(Dy) 0.63158–0.63158
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:co7dy12
tdb: tdb:CoDy-96Su.tdb:CO7DY12, tdb:CoDy-98Su.tdb:CO7DY12

TDB models of CO7DY12 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO7DY12, type code %A, sha256 6bdfab6e817c7d70…

74: PHASE CO7DY12 %A 2 7 12 !
75: CONST CO7DY12 : CO : DY : !

CoDy-98Su.tdb: CO7DY12, type code %A, sha256 ef3d3e66257222b3…

78: PHASE CO7DY12 %A 2 7 12 !
79: CONST CO7DY12 : CO : DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CO7DY2 (Co–Dy)

Id: phase:co-dy:co7dy2; status assigned
Structure: Co7Gd2 · hR18 · R-3m (166); type st:co7gd2-hr18; 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
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, Dy 0.2222
Stability: stable in 2 of 2 calculated diagram(s): 300–1615.53 K, x(Dy) 0.22222–0.22222
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:co7dy2
tdb: tdb:CoDy-96Su.tdb:CO7DY2, tdb:CoDy-98Su.tdb:CO7DY2

TDB models of CO7DY2 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CO7DY2, type code %A, sha256 6bdfab6e817c7d70…

59: PHASE CO7DY2 %A 2 7 2 !
60: CONST CO7DY2 : CO : DY : !

CoDy-98Su.tdb: CO7DY2, type code %A, sha256 ef3d3e66257222b3…

63: PHASE CO7DY2 %A 2 7 2 !
64: CONST CO7DY2 : CO : DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

CODY3_D011 (Co–Dy)

Id: phase:co-dy:cody3-d011; status assigned
Structure: Fe3C · D0_11 · oP16 · Pnma (62); type st:d0-11-fe3c-op16; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaabkufg and oqmd-18446, space group 62
Stoichiometry: Co 0.2500, Dy 0.7500
Stability: stable in 2 of 2 calculated diagram(s): 300–1143.89 K, x(Dy) 0.75–0.75
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:co-dy:cody3-d011
mp: mp:mp-aaabkufg
oqmd: oqmd:oqmd-18446
tdb: tdb:CoDy-96Su.tdb:CODY3_D011, tdb:CoDy-98Su.tdb:CODY3_D011

TDB models of CODY3_D011 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: CODY3_D011, type code %A, sha256 6bdfab6e817c7d70…

79: PHASE CODY3_D011 %A 2 1 3 !
80: CONST CODY3_D011 : CO : DY : !

CoDy-98Su.tdb: CODY3_D011, type code %A, sha256 ef3d3e66257222b3…

83: PHASE CODY3_D011 %A 2 1 3 !
84: CONST CODY3_D011 : CO : DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

FCC_A1 (Co–Dy)

Id: phase:co-dy: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 2 of 2 calculated diagram(s): 632.49–1773.89 K, x(Dy) 0–0.00174
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:fcc-a1
tdb: tdb:CoDy-96Su.tdb:FCC_A1, tdb:CoDy-98Su.tdb:FCC_A1

TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: FCC_A1, type code %A, sha256 6bdfab6e817c7d70…

34: PHASE FCC_A1 %A 2 1 1 !
35: CONST FCC_A1 : CO% DY : VA : !

CoDy-98Su.tdb: FCC_A1, type code %A, sha256 ef3d3e66257222b3…

42: PHASE FCC_A1 %A 2 1 1 !
43: CONST FCC_A1 : CO% DY : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

HCP_A3 (Co–Dy)

Id: phase:co-dy: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 2 of 2 calculated diagram(s): 300–1689.99 K, x(Dy) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:hcp-a3
tdb: tdb:CoDy-96Su.tdb:HCP_A3, tdb:CoDy-98Su.tdb:HCP_A3

TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written

CoDy-96Su.tdb: HCP_A3, type code %A, sha256 6bdfab6e817c7d70…

44: PHASE HCP_A3 %A 2 1 0.5 !
45: CONST HCP_A3 : CO% DY% : VA : !

CoDy-98Su.tdb: HCP_A3, type code %A, sha256 ef3d3e66257222b3…

52: PHASE HCP_A3 %A 2 1 0.5 !
53: CONST HCP_A3 : CO% DY% : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
assessment that models this phase

LIQUID (Co–Dy)

Id: phase:co-dy:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 993.35–2500 K, x(Dy) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:co-dy:liquid
tdb: tdb:CoDy-96Su.tdb:LIQUID, tdb:CoDy-98Su.tdb:LIQUID

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

CoDy-96Su.tdb: LIQUID, type code %, sha256 6bdfab6e817c7d70…

29: PHASE LIQUID:L % 1 1 !
30: CONST LIQUID:L : CO DY : !

CoDy-98Su.tdb: LIQUID, type code %, sha256 ef3d3e66257222b3…

37: PHASE LIQUID:L % 1 1 !
38: CONST LIQUID:L : CO DY : !

Example references (1 of 1; assessments first):

doi:10.3139/ijmr-1998-0099 X. Su, W. Zhang, Z. Du, Z. Metallkd., 89, 522-26(1998).
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). doi: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). doi: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.

@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}
}