Cu–Y phases

10 phases (tier A 3, tier C 1, liquid 1, needs_review 5); 10 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 · Cu–Y system page · Markdown · field reference

Phases of the Cu–Y system (10)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
BCC_A2 phase:cu-y:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1751.15–2499.9 K, x(Y) 1–1	0	1
CU2Y_H phase:cu-y:cu2y-h		needs_review	stable in 1 of 1 calculated diagram(s): 1128–1172.87 K, x(Y) 0.33333–0.33333	14	1
CU2Y_R phase:cu-y:cu2y-r	Hg2K · oI12 · Imma (74)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1128 K, x(Y) 0.33333–0.33333	10	1
CU4Y phase:cu-y:cu4y		needs_review	stable in 1 of 1 calculated diagram(s): 300–1244.31 K, x(Y) 0.2–0.2	15	1
CU6Y phase:cu-y:cu6y		needs_review	stable in 1 of 1 calculated diagram(s): 300–1184.64 K, x(Y) 0.12878–0.15945	13	1
CU7Y2 phase:cu-y:cu7y2		needs_review	stable in 1 of 1 calculated diagram(s): 300–1199.13 K, x(Y) 0.22222–0.22222	9	1
CUY_B2 phase:cu-y:cuy-b2		needs_review	stable in 1 of 1 calculated diagram(s): 300–1222.1 K, x(Y) 0.5–0.5	16	1
FCC_A1 phase:cu-y:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1358.77 K, x(Y) 0–0	8	1
HCP_A3 phase:cu-y:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1751.15 K, x(Y) 1–1	5	1
LIQUID phase:cu-y:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1077.1–2500 K, x(Y) 0–1	51	1

BCC_A2 (Cu–Y)

Id: phase:cu-y: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 1 of 1 calculated diagram(s): 1751.15–2499.9 K, x(Y) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:cu-y:bcc-a2
tdb: tdb:CuY-94Fri-LB.tdb:BCC_A2

TDB models of BCC_A2 (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: BCC_A2, type code %B, sha256 a8f5ab09a715225a…

39: PHASE BCC_A2 %B 2 1 3 !
40: CONST BCC_A2 : CU Y% : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase

CU2Y_H (Cu–Y)

Id: phase:cu-y:cu2y-h; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:H; no_structure_token; sgte_mmc2_row_incomplete
Candidate (dft_mp): Imma (74) — on-hull MP YCu2 at x(Y)=0.3333
Candidate (dft_oqmd): Imma (74) — on-hull OQMD Cu2 Y1 at x(Y)=0.3333
Candidate (literature_printed): (Cu2Y-h) · hP* — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Cu2Y-h) — Hallstedt 2025 mmc2 row for CU2Y_H: Cu2Y (high T)
Stoichiometry: Cu 0.6667, Y 0.3333
Stability: stable in 1 of 1 calculated diagram(s): 1128–1172.87 K, x(Y) 0.33333–0.33333
Literature: 14 values (14 accepted) from 2 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:cu-y:cu2y-h
paper: paper:10.1007/bf02647621:YCu2, paper:10.1007/bf02647621:YCu2(h), paper:sha256-85fd53a1a176b694:Cu2Y-H
tdb: tdb:CuY-94Fri-LB.tdb:CU2Y_H

TDB models of CU2Y_H (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CU2Y_H, type code %, sha256 a8f5ab09a715225a…

69: PHASE CU2Y_H % 2 2 1 !
70: CONST CU2Y_H : CU : Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

CU2Y_R (Cu–Y)

Id: phase:cu-y:cu2y-r; status assigned
Structure: Hg2K · oI12 · Imma (74); type st:hg2k-oi12; 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 (name_has_descriptive_tokens:R, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Cu 0.6667, Y 0.3333
Stability: stable in 1 of 1 calculated diagram(s): 300–1128 K, x(Y) 0.33333–0.33333
Literature: 10 values (8 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:cu2y-r
paper: paper:10.1007/bf02647621:YCu2(r), paper:sha256-85fd53a1a176b694:Cu2Y-R
tdb: tdb:CuY-94Fri-LB.tdb:CU2Y_R

TDB models of CU2Y_R (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CU2Y_R, type code %, sha256 a8f5ab09a715225a…

64: PHASE CU2Y_R % 2 2 1 !
65: CONST CU2Y_R : CU : Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

CU4Y (Cu–Y)

Id: phase:cu-y:cu4y; status needs_review
No structure assigned. Why: no_on_hull_entry_in_mp; no_structure_token; sgte_mmc2_row_incomplete
Candidate (dft_oqmd): C2/m (12) — on-hull OQMD Cu4 Y1 at x(Y)=0.2000
Candidate (literature_printed): (Cu4Y) · ? — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Cu4Y) — Hallstedt 2025 mmc2 row for CU4Y: Cu4Y
Stoichiometry: Cu 0.8000, Y 0.2000
Stability: stable in 1 of 1 calculated diagram(s): 300–1244.31 K, x(Y) 0.2–0.2
Literature: 15 values (15 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:cu4y
paper: paper:10.1007/bf02647621:YCu4, paper:sha256-85fd53a1a176b694:Cu4Y
tdb: tdb:CuY-94Fri-LB.tdb:CU4Y

TDB models of CU4Y (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CU4Y, type code %, sha256 a8f5ab09a715225a…

54: PHASE CU4Y % 2 4 1 !
55: CONST CU4Y : CU : Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

CU6Y (Cu–Y)

Id: phase:cu-y:cu6y; status needs_review
No structure assigned. Why: assessment_declared_compound_differs_from_site_ratios; no_structure_token; off_stoichiometric_model
Candidate (literature_printed): Cu7Tb · hP8 — printed with a label mapped to this phase
Candidate (sgte_mmc2): Cu7Tb · hP8 · P6/mmm (191) — Hallstedt 2025 mmc2 row for CU6Y: Cu6Y
Candidate (tdb_comment): Cu7Tb · hP8 · P6/mmm — CuY-94Fri-LB.tdb: 'Prototype Cu7Tb (hP8, P6/mmm)'
Stability: stable in 1 of 1 calculated diagram(s): 300–1184.64 K, x(Y) 0.12878–0.15945
Literature: 13 values (13 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:cu6y
paper: paper:10.1007/bf02647621:YCu6, paper:sha256-85fd53a1a176b694:Cu6Y
tdb: tdb:CuY-94Fri-LB.tdb:CU6Y

TDB models of CU6Y (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CU6Y, type code %, sha256 a8f5ab09a715225a…

49: PHASE CU6Y % 2 5 1 !
50: CONST CU6Y : CU : CU2 Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

CU7Y2 (Cu–Y)

Id: phase:cu-y:cu7y2; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (literature_printed): (Cu7Y2) · ? — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Cu7Y2) — Hallstedt 2025 mmc2 row for CU7Y2: Cu7Y2
Stoichiometry: Cu 0.7778, Y 0.2222
Stability: stable in 1 of 1 calculated diagram(s): 300–1199.13 K, x(Y) 0.22222–0.22222
Literature: 9 values (9 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:cu7y2
paper: paper:10.1007/bf02647621:Y2Cu7, paper:sha256-85fd53a1a176b694:Cu7Y2
tdb: tdb:CuY-94Fri-LB.tdb:CU7Y2

TDB models of CU7Y2 (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CU7Y2, type code %, sha256 a8f5ab09a715225a…

59: PHASE CU7Y2 % 2 7 2 !
60: CONST CU7Y2 : CU : Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

CUY_B2 (Cu–Y)

Id: phase:cu-y:cuy-b2; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:name_suggests_B2_but_dft_space_group_62; name_suggests_B2_but_dft_space_group_62
Candidate (dft_mp): Pnma (62) — on-hull MP YCu at x(Y)=0.5000
Candidate (dft_oqmd): Pnma (62) — on-hull OQMD Cu1 Y1 at x(Y)=0.5000
Candidate (literature_printed): CsCl · cP2 — printed with a label mapped to this phase
Candidate (name_token): CsCl · B2 · cP2 · Pm-3m (221) — Strukturbericht/word 'B2' in the TDB name
Candidate (sgte_mmc2): CsCl · B2 · cP2 · Pm-3m (221) — Hallstedt 2025 mmc2 row for CUY_B2: CuY
Candidate (tdb_comment): CsCl · cP2 · Pm3m — CuY-94Fri-LB.tdb: 'Prototype CsCl (cP2, Pm3m)'
Stoichiometry: Cu 0.5000, Y 0.5000
Stability: stable in 1 of 1 calculated diagram(s): 300–1222.1 K, x(Y) 0.5–0.5
Literature: 16 values (14 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:cuy-b2
paper: paper:10.1007/bf02647621:YCu, paper:sha256-85fd53a1a176b694:CuY
tdb: tdb:CuY-94Fri-LB.tdb:CUY_B2

TDB models of CUY_B2 (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: CUY_B2, type code %, sha256 a8f5ab09a715225a…

74: PHASE CUY_B2 % 2 1 1 !
75: CONST CUY_B2 : CU : Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

FCC_A1 (Cu–Y)

Id: phase:cu-y: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 1 of 1 calculated diagram(s): 300–1358.77 K, x(Y) 0–0
Literature: 8 values (8 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:fcc-a1
paper: paper:10.1007/bf02647621:(Cu), paper:sha256-85fd53a1a176b694:fcc-A1
tdb: tdb:CuY-94Fri-LB.tdb:FCC_A1

TDB models of FCC_A1 (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: FCC_A1, type code %A, sha256 a8f5ab09a715225a…

34: PHASE FCC_A1 %A 2 1 1 !
35: CONST FCC_A1 : CU% Y : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

HCP_A3 (Cu–Y)

Id: phase:cu-y: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 1 of 1 calculated diagram(s): 300–1751.15 K, x(Y) 1–1
Literature: 5 values (5 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:hcp-a3
paper: paper:10.1007/bf02647621:Y, paper:sha256-85fd53a1a176b694:hcp-A3
tdb: tdb:CuY-94Fri-LB.tdb:HCP_A3

TDB models of HCP_A3 (1): PHASE and CONSTITUENT statements as written

CuY-94Fri-LB.tdb: HCP_A3, type code %A, sha256 a8f5ab09a715225a…

44: PHASE HCP_A3 %A 2 1 0.5 !
45: CONST HCP_A3 : CU Y% : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for this phase

LIQUID (Cu–Y)

Id: phase:cu-y:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1077.1–2500 K, x(Y) 0–1
Literature: 51 values (49 accepted) from 2 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-y:liquid
paper: paper:10.1007/bf02647621:L, paper:sha256-85fd53a1a176b694:Liquid
tdb: tdb:CuY-94Fri-LB.tdb:LIQUID

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

CuY-94Fri-LB.tdb: LIQUID, type code %, sha256 a8f5ab09a715225a…

29: PHASE LIQUID:L % 1 1 !
30: CONST LIQUID:L : CU Y : !

Example references (1 of 1; assessments first):

doi:10.1007/BF02647621 S.G. Fries, H.L. Lukas, R. Konetzki, R. Schmid-Fetzer, J. Phase Equilib., 15, 606-14(1994).
assessment that models this phase; reports values for 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}
}