Cu–Gd system

46 accepted literature values from 2 paper(s) (experimental 14, model 13, DFT 1, unspecified 18); 1 calculated phase diagram(s).

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (11) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	14
model	13
DFT	1
unspecified	18

Accepted values by property group
Property group	Values
invariant reaction	32
formation	2
crystal structure	12

Calculated phase diagrams

Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model.

Assessments with a calculated phase diagram
TDB file	Assessment	SHA-256	Links
CuGd-09Zha.tdb	L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Calphad, 33, 664-72(2009). doi:10.1016/j.calphad.2009.08.003	`2fc893a4bb823006483f9c890805da817bfe4546301f4598053eb3d8e51d0b9e`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
CuGd-09Zha.tdb	1569.02	HCP_A3 (x(Gd) 1) + LIQUID (x(Gd) 1) + BCC_A2 (x(Gd) 1)
CuGd-09Zha.tdb	1195.71	LIQUID (x(Gd) 0.1644) + CU5GD_D2D (x(Gd) 0.16667) + CU9GD2 (x(Gd) 0.18182)
CuGd-09Zha.tdb	1195.7	LIQUID (x(Gd) 0.16469) + CU5GD_D2D (x(Gd) 0.16667) + CU9GD2 (x(Gd) 0.18182)
CuGd-09Zha.tdb	1195.7	LIQUID (x(Gd) 0.16479) + CU5GD_D2D (x(Gd) 0.16667) + CU9GD2 (x(Gd) 0.18182)
CuGd-09Zha.tdb	1147.06	CU9GD2 (x(Gd) 0.18182) + CU7GD2 (x(Gd) 0.22222) + LIQUID (x(Gd) 0.25009)
CuGd-09Zha.tdb	1147.05	CU9GD2 (x(Gd) 0.18182) + CU7GD2 (x(Gd) 0.22222) + LIQUID (x(Gd) 0.25018)
CuGd-09Zha.tdb	1135.5	LIQUID (x(Gd) 0.10203) + CU6GD (x(Gd) 0.14286) + CU5GD_D2D (x(Gd) 0.16667)
CuGd-09Zha.tdb	1135.5	LIQUID (x(Gd) 0.10195) + CU6GD (x(Gd) 0.14286) + CU5GD_D2D (x(Gd) 0.16667)
CuGd-09Zha.tdb	1135.5	LIQUID (x(Gd) 0.10189) + CU6GD (x(Gd) 0.14286) + CU5GD_D2D (x(Gd) 0.16667)
CuGd-09Zha.tdb	1135.5	LIQUID (x(Gd) 0.10189) + CU6GD (x(Gd) 0.14286) + CU5GD_D2D (x(Gd) 0.16667)
CuGd-09Zha.tdb	1123.59	FCC_A1 (x(Gd) 3.000e-5) + LIQUID (x(Gd) 0.09356) + CU6GD (x(Gd) 0.14286)
CuGd-09Zha.tdb	1123.59	FCC_A1 (x(Gd) 3.000e-5) + LIQUID (x(Gd) 0.09355) + CU6GD (x(Gd) 0.14286)
CuGd-09Zha.tdb	1104.93	CU9GD2 (x(Gd) 0.18182) + CU7GD2 (x(Gd) 0.22222) + LIQUID (x(Gd) 0.27516)
CuGd-09Zha.tdb	1104.93	CU9GD2 (x(Gd) 0.18182) + CU7GD2 (x(Gd) 0.22222) + LIQUID (x(Gd) 0.27528)
CuGd-09Zha.tdb	1104.93	CU9GD2 (x(Gd) 0.18182) + CU7GD2 (x(Gd) 0.22222) + LIQUID (x(Gd) 0.27523)
CuGd-09Zha.tdb	1094.51	CU9GD2 (x(Gd) 0.18182) + LIQUID (x(Gd) 0.28061) + CU2GD (x(Gd) 0.33333)
CuGd-09Zha.tdb	1094.51	CU9GD2 (x(Gd) 0.18182) + LIQUID (x(Gd) 0.28039) + CU2GD (x(Gd) 0.33333)
CuGd-09Zha.tdb	1094.51	CU9GD2 (x(Gd) 0.18182) + LIQUID (x(Gd) 0.28069) + CU2GD (x(Gd) 0.33333)
CuGd-09Zha.tdb	1046.36	CU2GD (x(Gd) 0.33333) + LIQUID (x(Gd) 0.42593) + CUGD_B2 (x(Gd) 0.5)
CuGd-09Zha.tdb	1046.36	CU2GD (x(Gd) 0.33333) + LIQUID (x(Gd) 0.42572) + CUGD_B2 (x(Gd) 0.5)
CuGd-09Zha.tdb	933.64	CU5GD_D2D (x(Gd) 0.16667) + CU5GD_C15B (x(Gd) 0.16667) + CU9GD2 (x(Gd) 0.18182)
CuGd-09Zha.tdb	933.64	CU6GD (x(Gd) 0.14286) + CU5GD_C15B (x(Gd) 0.16667) + CU5GD_D2D (x(Gd) 0.16667)
CuGd-09Zha.tdb	931.34	CUGD_B2 (x(Gd) 0.5) + LIQUID (x(Gd) 0.65771) + BCC_A2 (x(Gd) 0.8676)
CuGd-09Zha.tdb	872.45	CUGD_B2 (x(Gd) 0.5) + BCC_A2 (x(Gd) 0.8734) + HCP_A3 (x(Gd) 0.94984)
CuGd-09Zha.tdb	872.45	CUGD_B2 (x(Gd) 0.5) + BCC_A2 (x(Gd) 0.87345) + HCP_A3 (x(Gd) 0.94987)

Convex hulls: Materials Project DFT hull · OQMD DFT hull

Invariant reactions (literature)

Invariant reactions reported in the literature for the Cu–Gd system (32)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1205	congruent melting: L -> Cu9Gd2	L: Cu 0.818182, Gd 0.181818; Cu9Gd2: Cu 0.818182, Gd 0.181818	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 13 report
1203	congruent melting: L -> Cu9Gd2	L: Cu 0.818182, Gd 0.181818; Cu9Gd2: Cu 0.818182, Gd 0.181818	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 12 report
1201	congruent melting: L -> Cu9Gd2	L: Cu 0.818182, Gd 0.181818; Cu9Gd2: Cu 0.818182, Gd 0.181818	model	[1] Zhang 2009	Table 3, p. 7, row 11 report
1198	peritectic: L + Cu9Gd2 -> Cu5Gd_H	L: Gd 0.167; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu5Gd_H: Cu 0.833333, Gd 0.166667	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 8 report
1196	peritectic: L + Cu9Gd2 -> Cu5Gd_H	L: Gd 0.162; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu5Gd_H: Cu 0.833333, Gd 0.166667	model	[1] Zhang 2009	Table 3, p. 7, row 7 report
1159	peritectic: L + Cu5Gd_H -> Cu6Gd	L: Gd 0.095; Cu5Gd_H: Cu 0.833333, Gd 0.166667; Cu6Gd: Cu 0.857143, Gd 0.142857	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 6 report
1148	eutectic: L -> Fcc_Cu + Cu6Gd	L: Gd 0.09; Cu6Gd: Cu 0.857143, Gd 0.142857	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 3 report
1147	peritectic: L + Cu9Gd2 -> Cu7Gd2	L: Gd 0.252; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu7Gd2: Cu 0.777778, Gd 0.222222	model	[1] Zhang 2009	Table 3, p. 7, row 14 report
1143	peritectic: L -> Cu9Gd2 + Cu2Gd	L: Gd 0.605; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu2Gd: Cu 0.666667, Gd 0.333333	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 20 report
1143	peritectic: L + Cu9Gd2 -> Cu7Gd2	L: Gd 0.265; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu7Gd2: Cu 0.777778, Gd 0.222222	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 15 report
1139	peritectic: L + Cu5Gd_H -> Cu6Gd	L: Gd 0.103; Cu5Gd_H: Cu 0.833333, Gd 0.166667; Cu6Gd: Cu 0.857143, Gd 0.142857	model	[1] Zhang 2009	Table 3, p. 7, row 4 report
1138	peritectic: L + Cu5Gd_H -> Cu6Gd	L: Gd 0.1; Cu5Gd_H: Cu 0.833333, Gd 0.166667; Cu6Gd: Cu 0.857143, Gd 0.142857	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 5 report
1133	eutectic: L -> Fcc_Cu + Cu6Gd	L: Gd 0.095; Cu6Gd: Cu 0.857143, Gd 0.142857	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 2 report
1133	congruent melting: L -> Cu2Gd	L: Cu 0.666667, Gd 0.333333; Cu2Gd: Cu 0.666667, Gd 0.333333	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 22 report
1129	congruent melting: L -> Cu2Gd	L: Cu 0.666667, Gd 0.333333; Cu2Gd: Cu 0.666667, Gd 0.333333	model	[1] Zhang 2009	Table 3, p. 7, row 21 report
1125	eutectic: L -> Fcc_Cu + Cu6Gd	L: Gd 0.093; Cu6Gd: Cu 0.857143, Gd 0.142857	model	[1] Zhang 2009	Table 3, p. 7, row 1 report
1106	congruent melting: L -> CuGd	L: Cu 0.5, Gd 0.5; CuGd: Cu 0.5, Gd 0.5	model	[1] Zhang 2009	Table 3, p. 7, row 26 report
1105	metatectic/catatectic: Cu7Gd2 -> L + Cu9Gd2	Cu7Gd2: Cu 0.777778, Gd 0.222222; L: Gd 0.277; Cu9Gd2: Cu 0.818182, Gd 0.181818	model	[1] Zhang 2009	Table 3, p. 7, row 16 report
1103	congruent melting: L -> CuGd	L: Cu 0.5, Gd 0.5; CuGd: Cu 0.5, Gd 0.5	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 27 report
1098	metatectic/catatectic: Cu7Gd2 -> L + Cu9Gd2	Cu7Gd2: Cu 0.777778, Gd 0.222222; Cu9Gd2: Cu 0.818182, Gd 0.181818	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 17 report
1098	eutectic: L -> Cu9Gd2 + Cu2Gd	L: Gd 0.28; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu2Gd: Cu 0.666667, Gd 0.333333	model	[1] Zhang 2009	Table 3, p. 7, row 18 report
1093	eutectic: L -> Cu9Gd2 + Cu2Gd	L: Gd 0.29; Cu9Gd2: Cu 0.818182, Gd 0.181818; Cu2Gd: Cu 0.666667, Gd 0.333333	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 19 report
1052	eutectic: L -> Cu2Gd + CuGd	L: Gd 0.425; Cu2Gd: Cu 0.666667, Gd 0.333333; CuGd: Cu 0.5, Gd 0.5	model	[1] Zhang 2009	Table 3, p. 7, row 23 report
1043	eutectic: L -> Cu2Gd + CuGd	L: Gd 0.44; Cu2Gd: Cu 0.666667, Gd 0.333333; CuGd: Cu 0.5, Gd 0.5	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 24 report
1032	peritectic: L -> Cu2Gd + CuGd	Cu2Gd: Cu 0.666667, Gd 0.333333; CuGd: Cu 0.5, Gd 0.5	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 25 report
948	eutectic: L -> CuGd + Bcc_Gd	L: Gd 0.7; CuGd: Cu 0.5, Gd 0.5	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 29 report
941	eutectic: L -> CuGd + Bcc_Gd	L: Gd 0.685; CuGd: Cu 0.5, Gd 0.5	unspecified	[1] Zhang 2009 cites Cheng 1983	Table 3, p. 7, row 30 report
941	eutectic: L -> CuGd + Bcc_Gd	L: Gd 0.658; CuGd: Cu 0.5, Gd 0.5	model	[1] Zhang 2009	Table 3, p. 7, row 28 report
935	polymorphic: Cu5Gd_H -> Cu5Gd_L	Cu5Gd_H: Cu 0.833333, Gd 0.166667; Cu5Gd_L: Cu 0.833333, Gd 0.166667	model	[1] Zhang 2009	Table 3, p. 7, row 9 report
933	polymorphic: Cu5Gd_H -> Cu5Gd_L	Cu5Gd_H: Cu 0.833333, Gd 0.166667; Cu5Gd_L: Cu 0.833333, Gd 0.166667	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 10 report
912	eutectoid: Bcc_Gd -> CuGd + Hcp_Gd	CuGd: Cu 0.5, Gd 0.5	model	[1] Zhang 2009	Table 3, p. 7, row 31 report
903	eutectoid: Bcc_Gd -> CuGd + Hcp_Gd	CuGd: Cu 0.5, Gd 0.5	experimental	[1] Zhang 2009 cites Carnasciali 1983 doi	Table 3, p. 7, row 32 report

Formation enthalpies

Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from dft_parity.json.

Enthalpies of formation, Cu–Gd system (2)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location	Quote
CuGd		-26.4 kJ/mol-atom	0	DFT			[2] Palumbo 2009	Table 2, p. 4, row 20 report
CuGd	CuGd	-10.6 kJ/mol-atom	298.15	experimental	-20.386 (mp-aaabiyyx)	-22.451 (oqmd-1976400)	[2] Palumbo 2009 cites Sommer 2009	Table 2, p. 4, row 21 report

Other properties

Crystal structure (12)

Crystal structure, Cu–Gd system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	4.32 Å	298.15	Cu2Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 18 report
Lattice a	5.02 Å	298.15	Cu5Gd_H	unspecified	[1] Zhang 2009	Table 1, p. 3, row 15 report
Lattice a	7.06 Å	298.15	Cu5Gd_L	unspecified	[1] Zhang 2009	Table 1, p. 3, row 14 report
Lattice a	8.03 Å	298.15	Cu6Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 13 report
Lattice a	5 Å	298.15	Cu9Gd2	unspecified	[1] Zhang 2009	Table 1, p. 3, row 16 report
Lattice a	3.501 Å	298.15	CuGd alloy: Cu 0.5, Gd 0.5	unspecified	[1] Zhang 2009	Table 1, p. 3, row 19 report
Lattice b	6.86 Å	298.15	Cu2Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 18 report
Lattice b	5.02 Å	298.15	Cu6Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 13 report
Lattice c	7.33 Å	298.15	Cu2Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 18 report
Lattice c	4.12 Å	298.15	Cu5Gd_H	unspecified	[1] Zhang 2009	Table 1, p. 3, row 15 report
Lattice c	9.995 Å	298.15	Cu6Gd	unspecified	[1] Zhang 2009	Table 1, p. 3, row 13 report
Lattice c	13.9 Å	298.15	Cu9Gd2	unspecified	[1] Zhang 2009	Table 1, p. 3, row 16 report

Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009). doi:10.1016/j.calphad.2009.08.003
M. Palumbo, L. Battezzati, A. Pasturel, S. Gottlieb-Schönmeyer, W. Assmus, Thermodynamic and ab initio investigation of the Cu–Dy system, Calphad 33, 511-516 (2009). doi:10.1016/j.calphad.2009.04.001

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735569
R. Arróyave, J. Saal, D. Shin, ORCHID-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735859
R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735891
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 the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); 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). 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_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_phase_diagrams_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Diagrams: calculated binary phase diagrams}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735859},
  url       = {https://doi.org/10.5281/zenodo.23735859}
}

@misc{orchid_hulls_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735891},
  url       = {https://doi.org/10.5281/zenodo.23735891}
}

@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}
}