Cu–Ge system

19 accepted literature values from 1 paper(s) (experimental 10, model 9); 2 calculated phase diagram(s). 2 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (9) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	10
model	9

Accepted values by property group
Property group	Values
invariant reaction	14
phase transition	2
formation	3

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
CuGe-10Wan.tdb	J. Wang, S. Jin, C. Leinenbach, A. Jacot, J. Alloys Compd., 504, 159-65(2010). doi:10.1016/j.jallcom.2010.05.077	`af99f4c24e73a88ee53be79cd710fe5908dddfb0e8b133606ce2e473b1f58c89`	viewer · TDB · JSON
CuGe-Rand.tdb	M.H. Rand, unpublished.	`39799a146bda7651414fcf51081fe0fe39ca7e2fab06e0050e19f1ce92e6b3a0`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
CuGe-10Wan.tdb	1097.3	FCC_A1 (x(Ge) 0.11795) + HCP_A3 (x(Ge) 0.12762) + LIQUID (x(Ge) 0.18009)
CuGe-10Wan.tdb	1022.16	HCP_A3 (x(Ge) 0.16434) + LIQUID (x(Ge) 0.23251) + CU3GE_D018 (x(Ge) 0.235)
CuGe-10Wan.tdb	1022.16	HCP_A3 (x(Ge) 0.16419) + LIQUID (x(Ge) 0.2323) + CU3GE_D018 (x(Ge) 0.235)
CuGe-10Wan.tdb	970.46	CU3GE_D018 (x(Ge) 0.235) + CU3GE_D03 (x(Ge) 0.265) + LIQUID (x(Ge) 0.32065)
CuGe-10Wan.tdb	947.61	CU3GE_D018 (x(Ge) 0.235) + CU3GE_D0A (x(Ge) 0.25) + CU3GE_D03 (x(Ge) 0.265)
CuGe-10Wan.tdb	911.01	CU3GE_D03 (x(Ge) 0.265) + LIQUID (x(Ge) 0.38889) + DIAMOND_A4 (x(Ge) 1)
CuGe-10Wan.tdb	884.79	CU3GE_D0A (x(Ge) 0.25) + CU3GE_D03 (x(Ge) 0.265) + DIAMOND_A4 (x(Ge) 1)
CuGe-10Wan.tdb	822.46	HCP_A3 (x(Ge) 0.15491) + CU3GE_D018 (x(Ge) 0.235) + CU3GE_D0A (x(Ge) 0.25)
CuGe-10Wan.tdb	822.46	HCP_A3 (x(Ge) 0.1549) + CU3GE_D018 (x(Ge) 0.235) + CU3GE_D0A (x(Ge) 0.25)
CuGe-Rand.tdb	1097.53	FCC_A1 (x(Ge) 0.1167) + HCP_A3 (x(Ge) 0.13178) + LIQUID (x(Ge) 0.17961)
CuGe-Rand.tdb	1017.11	HCP_A3 (x(Ge) 0.1856) + CU3GE (x(Ge) 0.25) + LIQUID (x(Ge) 0.25082)
CuGe-Rand.tdb	1017.11	HCP_A3 (x(Ge) 0.1857) + CU3GE (x(Ge) 0.25) + LIQUID (x(Ge) 0.25095)
CuGe-Rand.tdb	908.02	CU3GE (x(Ge) 0.25) + LIQUID (x(Ge) 0.412) + DIAMOND_A4 (x(Ge) 1)
CuGe-Rand.tdb	908.02	CU3GE (x(Ge) 0.25) + LIQUID (x(Ge) 0.41203) + DIAMOND_A4 (x(Ge) 1)
CuGe-Rand.tdb	908.02	CU3GE (x(Ge) 0.25) + LIQUID (x(Ge) 0.41227) + DIAMOND_A4 (x(Ge) 1)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull CuGe-Rand

Invariant reactions (literature)

Invariant reactions reported in the literature for the Cu–Ge system (14)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1097	peritectic: L + fcc <-> hcp	L: Ge 0.18	model	[1] Wang 2010	Table 1, p. 2, row 2 report
1097	peritectic: L + fcc <-> hcp	L: Ge 0.175	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 1 report
1021	eutectic: L <-> hcp + ε-Cu0.765Ge0.235	L: Ge 0.232; ε-Cu0.765Ge0.235: Ge 0.235	model	[1] Wang 2010	Table 1, p. 2, row 6 report
1016	eutectic: L <-> hcp + ε-Cu0.765Ge0.235	L: Ge 0.219; ε-Cu0.765Ge0.235: Ge 0.235	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 5 report
971	peritectic: L + ε-Cu0.765Ge0.235 <-> θ-Cu0.735Ge0.265	L: Ge 0.32; ε-Cu0.765Ge0.235: Ge 0.235; θ-Cu0.735Ge0.265: Ge 0.265	model	[1] Wang 2010	Table 1, p. 2, row 8 report
971	peritectic: L + ε-Cu0.765Ge0.235 <-> θ-Cu0.735Ge0.265	L: Ge 0.303; ε-Cu0.765Ge0.235: Ge 0.235; θ-Cu0.735Ge0.265: Ge 0.265	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 7 report
948	peritectoid: ε-Cu0.765Ge0.235 + θ-Cu0.735Ge0.265 <-> η-Cu0.75Ge0.25	ε-Cu0.765Ge0.235: Ge 0.235; θ-Cu0.735Ge0.265: Ge 0.265; η-Cu0.75Ge0.25: Ge 0.25	model	[1] Wang 2010	Table 1, p. 2, row 14 report
917	eutectic: L <-> θ-Cu0.735Ge0.265 + (Ge)	L: Ge 0.365; θ-Cu0.735Ge0.265: Ge 0.265; (Ge): Ge 1	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 9 report
911	eutectic: L <-> θ-Cu0.735Ge0.265 + (Ge)	L: Ge 0.389; θ-Cu0.735Ge0.265: Ge 0.265; (Ge): Ge 1	model	[1] Wang 2010	Table 1, p. 2, row 10 report
909	peritectoid: ε-Cu0.765Ge0.235 + θ-Cu0.735Ge0.265 <-> η-Cu0.75Ge0.25	ε-Cu0.765Ge0.235: Ge 0.235; θ-Cu0.735Ge0.265: Ge 0.265; η-Cu0.75Ge0.25: Ge 0.25	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 13 report
887	eutectoid: θ-Cu0.735Ge0.265 <-> η-Cu0.75Ge0.25 + (Ge)	θ-Cu0.735Ge0.265: Ge 0.265; η-Cu0.75Ge0.25: Ge 0.25; (Ge): Ge 1	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 15 report
885	eutectoid: θ-Cu0.735Ge0.265 <-> η-Cu0.75Ge0.25 + (Ge)	θ-Cu0.735Ge0.265: Ge 0.265; η-Cu0.75Ge0.25: Ge 0.25; (Ge): Ge 1	model	[1] Wang 2010	Table 1, p. 2, row 16 report
823	eutectoid: ε-Cu0.765Ge0.235 <-> hcp + η-Cu0.75Ge0.25	ε-Cu0.765Ge0.235: Ge 0.235; η-Cu0.75Ge0.25: Ge 0.25	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 11 report
822	eutectoid: ε-Cu0.765Ge0.235 <-> hcp + η-Cu0.75Ge0.25	ε-Cu0.765Ge0.235: Ge 0.235; η-Cu0.75Ge0.25: Ge 0.25	model	[1] Wang 2010	Table 1, p. 2, row 12 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–Ge system (3)
Phase	Value	T (K)	Class	Source	Location	Quote
␩-Cu0.75 Ge0.25	-7.66 kJ/mol (basis unstated)	780	experimental	[1] Wang 2010 cites Predel 1971 doi	p. 2 report	The enthalpy of formation of intermetallic compound ␩-Cu0.75 Ge0.25 was also obtained by Predel and Stein [21] at 780 K, which is -7660 J/mol at 25 at.% Ge.
␩-Cu0.75Ge0.25	-7.66 kJ/mol (basis unstated)	298.15	experimental	[1] Wang 2010 cites Predel 1971 doi	p. 6 report	The enthalpy of formation of solid alloys and intermetallic compounds in the Cu-Ge binary system at 298 K was calculated as presented in Fig. 10. As can be seen, the present calculated values in solid alloys are in excellent agreement with the experimental data measured by Predel and Stein [21,29] and Kleppa and King [31]. However, the calculated enthalpy of formation of the intermetallic compoun…
␩-Cu0.75Ge0.25	-4.245 kJ/mol (basis unstated)	298.15	model	[1] Wang 2010	p. 6 report	The enthalpy of formation of solid alloys and intermetallic compounds in the Cu-Ge binary system at 298 K was calculated as presented in Fig. 10. As can be seen, the present calculated values in solid alloys are in excellent agreement with the experimental data measured by Predel and Stein [21,29] and Kleppa and King [31]. However, the calculated enthalpy of formation of the intermetallic compoun…

Other properties

Phase transition (2)

Phase transition, Cu–Ge system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	1020 K	1020	congruent melting: L <-> ε-Cu0.765Ge0.235 L: Ge 0.22; ε-Cu0.765Ge0.235: Ge 0.235	experimental	[1] Wang 2010 cites Olesinski 1986 doi	Table 1, p. 2, row 3 report
Phase transition	1022 K	1022	congruent melting: L <-> ε-Cu0.765Ge0.235 L: Ge 0.235; ε-Cu0.765Ge0.235: Ge 0.235	model	[1] Wang 2010	Table 1, p. 2, row 4 report

Sources

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

J. Wang, S. Jin, C. Leinenbach, A. Jacot, Thermodynamic assessment of the Cu–Ge binary system, Journal of Alloys and Compounds 504, 159-165 (2010). doi:10.1016/j.jallcom.2010.05.077

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}
}