Ge–Nb system

45 accepted literature values from 2 paper(s) (experimental 21, model 19, DFT 5); 2 calculated phase diagram(s). 7 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	21
model	19
DFT	5

Accepted values by property group
Property group	Values
invariant reaction	30
phase equilibrium	5
formation	10

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
GeNb-11Gen.tdb	T. Geng, C. Li, Z. Du, C. Guo, X. Zhao, H. Xu, J. Alloys Compd., 509, 3080-88(2011). doi:10.1016/j.jallcom.2010.12.005	`55314e2cadc330d9cc399b689b0ed38dcc38c3845fdb8918c4599b9f0d9481e5`	viewer · TDB · JSON
GeNb-17Utt.tdb	C.A. Utton, I. Papadimitriou, H. Kinoshita, P. Tsakiropoulos, J. Alloys Compd., 717, 303-16(2017). doi:10.1016/j.jallcom.2017.04.279	`0c86fa883ab70ed8c2bbcb46d0c0cf0c5ba4c55edef0466e8d5c9196ea5dbeae`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
GeNb-11Gen.tdb	2291.56	LIQUID (x(Nb) 0.52605) + GE2NB3_D88 (x(Nb) 0.58971) + GE3NB5_D8M (x(Nb) 0.60679)
GeNb-11Gen.tdb	2176.65	LIQUID (x(Nb) 0.77822) + GENB3_A15 (x(Nb) 0.81873) + BCC_A2 (x(Nb) 0.88885)
GeNb-11Gen.tdb	2138.3	GE3NB5_D8M (x(Nb) 0.63035) + LIQUID (x(Nb) 0.74904) + GENB3_A15 (x(Nb) 0.76095)
GeNb-11Gen.tdb	1860.89	GE2NB_C40 (x(Nb) 0.34005) + LIQUID (x(Nb) 0.42066) + GE2NB3_D88 (x(Nb) 0.56993)
GeNb-11Gen.tdb	1210.78	DIAMOND_A4 (x(Nb) 0.00315) + LIQUID (x(Nb) 0.00532) + GE2NB_C40 (x(Nb) 0.32835)
GeNb-17Utt.tdb	2175.34	LIQUID (x(Nb) 0.78613) + GENB3_A15 (x(Nb) 0.81955) + BCC_A2 (x(Nb) 0.89344)
GeNb-17Utt.tdb	2135.63	GE3NB5_D8M (x(Nb) 0.62448) + LIQUID (x(Nb) 0.75115) + GENB3_A15 (x(Nb) 0.76694)
GeNb-17Utt.tdb	1852.92	GE2NB_C40 (x(Nb) 0.33729) + LIQUID (x(Nb) 0.43086) + GE3NB5_D8M (x(Nb) 0.60395)
GeNb-17Utt.tdb	1210.98	DIAMOND_A4 (x(Nb) 0.00262) + LIQUID (x(Nb) 0.00397) + GE2NB_C40 (x(Nb) 0.32834)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull GeNb-11Gen

Invariant reactions (literature)

Invariant reactions reported in the literature for the Ge–Nb system (30)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
2453.15	congruent melting: L <-> (Nb5Ge3)	L: Ge 0.38; (Nb5Ge3): Ge 0.38	experimental	[1] Geng 2011 cites Jorda 1978 doi	Table 1, p. 2, row 13 report
2453.15	congruent melting: L <-> (Nb5Ge3)	L: Ge 0.37; (Nb5Ge3): Ge 0.37	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 14 report
2452.15	congruent melting: L <-> (Nb5Ge3)	L: Ge 0.382; (Nb5Ge3): Ge 0.382	model	[1] Geng 2011	Table 1, p. 2, row 15 report
2423.15	congruent melting: L <-> (Nb5Ge3)	L: Ge 0.357; (Nb5Ge3): Ge 0.357	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 11 report
2338.15	congruent melting: L <-> (Nb5Ge3)	L: Ge 0.384; (Nb5Ge3): Ge 0.384	experimental	[1] Geng 2011 cites Muller 1970	Table 1, p. 2, row 12 report
2313.15	peritectic: L + (Nb5Ge3) <-> (Nb3Ge2)	L: Ge 0.468; (Nb5Ge3): Ge 0.393; (Nb3Ge2): Ge 0.41	model	[1] Geng 2011	Table 1, p. 2, row 30 report
2313.15	peritectic: L + (Nb5Ge3) <-> (Nb3Ge2)	L: Ge 0.457; (Nb5Ge3): Ge 0.357; (Nb3Ge2): Ge 0.409	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 29 report
2243.15	peritectic: L + Bcc-(Nb) <-> (Nb3Ge)	L: Ge 0.19; Bcc-(Nb): Ge 0.08; (Nb3Ge): Ge 0.18	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 1 report
2203.15	eutectic: L <-> (Nb3Ge) + (Nb5Ge3)	L: Ge 0.265; (Nb3Ge): Ge 0.2; (Nb5Ge3): Ge 0.334	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 6 report
2183.15	peritectic: L + Bcc-(Nb) <-> (Nb3Ge)	L: Ge 0.185; Bcc-(Nb): Ge 0.04; (Nb3Ge): Ge 0.183	experimental	[1] Geng 2011 cites Muller 1970	Table 1, p. 2, row 2 report
2176.15	peritectic: L + Bcc-(Nb) <-> (Nb3Ge)	L: Ge 0.22; Bcc-(Nb): Ge 0.111; (Nb3Ge): Ge 0.181	model	[1] Geng 2011	Table 1, p. 2, row 5 report
2173.15	peritectic: L + Bcc-(Nb) <-> (Nb3Ge)	L: Ge 0.22; Bcc-(Nb): Ge 0.115; (Nb3Ge): Ge 0.18	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 4 report
2173.15	eutectic: L <-> (Nb3Ge) + (Nb5Ge3)	L: Ge 0.218; (Nb3Ge): Ge 0.188; (Nb5Ge3): Ge 0.361	experimental	[1] Geng 2011 cites Muller 1970	Table 1, p. 2, row 7 report
2173.15	peritectic: L + Bcc-(Nb) <-> (Nb3Ge)	L: Ge 0.22; Bcc-(Nb): Ge 0.115; (Nb3Ge): Ge 0.18	experimental	[1] Geng 2011 cites Jorda 1978 doi	Table 1, p. 2, row 3 report
2138.15	eutectic: L <-> (Nb3Ge) + (Nb5Ge3)	L: Ge 0.25; (Nb3Ge): Ge 0.24; (Nb5Ge3): Ge 0.37	model	[1] Geng 2011	Table 1, p. 2, row 10 report
2138.15	eutectic: L <-> (Nb3Ge) + (Nb5Ge3)	L: Ge 0.27; (Nb3Ge): Ge 0.23; (Nb5Ge3): Ge 0.365	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 9 report
2138.15	eutectic: L <-> (Nb3Ge) + (Nb5Ge3)	L: Ge 0.27; (Nb3Ge): Ge 0.23; (Nb5Ge3): Ge 0.371	experimental	[1] Geng 2011 cites Jorda 1978 doi	Table 1, p. 2, row 8 report
1953.15	congruent melting: L <-> (NbGe2)	L: Ge 0.661; (NbGe2): Ge 0.661	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 23 report
1953.15	congruent melting: L <-> (NbGe2)	L: Ge 0.67; (NbGe2): Ge 0.67	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 21 report
1953.15	congruent melting: L <-> (NbGe2)	L: Ge 0.665; (NbGe2): Ge 0.665	experimental	[1] Geng 2011 cites Jorda 1978 doi	Table 1, p. 2, row 22 report
1953.15	congruent melting: L <-> (NbGe2)	L: Ge 0.667; (NbGe2): Ge 0.667	model	[1] Geng 2011	Table 1, p. 2, row 24 report
1863.15	eutectic: L <-> (Nb5Ge3) + (NbGe2)	(Nb5Ge3): Ge 0.375, Nb 0.625; (NbGe2): Ge 0.666667, Nb 0.333333	experimental	[1] Geng 2011 cites Feschotte 1979	Table 1, p. 2, row 18 report
1863.15	eutectic: L <-> (Nb3Ge2) + (NbGe2)	L: Ge 0.6; (Nb3Ge2): Ge 0.444; (NbGe2): Ge 0.668	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 16 report
1862.55	eutectic: L <-> (Nb5Ge3) + (NbGe2)	L: Ge 0.58; (Nb5Ge3): Ge 0.43; (NbGe2): Ge 0.66	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 20 report
1862.55	eutectic: L <-> (Nb3Ge2) + (NbGe2)	L: Ge 0.58; (Nb3Ge2): Ge 0.43; (NbGe2): Ge 0.66	model	[1] Geng 2011	Table 1, p. 2, row 17 report
1853.15	eutectic: L <-> (Nb5Ge3) + (NbGe2)	L: Ge 0.592; (Nb5Ge3): Ge 0.444; (NbGe2): Ge 0.662	experimental	[1] Geng 2011 cites Jorda 1978 doi	Table 1, p. 2, row 19 report
1223.15	peritectic: L + (NbGe2) <-> Diamond-(Ge)	L: Ge 1; (NbGe2): Ge 0.687; Diamond-(Ge): Ge 0.999	model	[1] Geng 2011 cites Okamoto 2000	Table 1, p. 2, row 28 report
1223.15	peritectic: L + (NbGe2) <-> Diamond-(Ge)	L: Ge 1; (NbGe2): Ge 0.687; Diamond-(Ge): Ge 0.999	experimental	[1] Geng 2011 cites Pan 1970	Table 1, p. 2, row 27 report
1210.95	eutectic: L <-> (NbGe2) + Diamond-(Ge)	L: Ge 0.995; (NbGe2): Ge 0.672; Diamond-(Ge): Ge 0.997	model	[1] Geng 2011	Table 1, p. 2, row 26 report
1210.15	eutectic: L <-> (NbGe2) + Diamond-(Ge)	L: Ge 1; (NbGe2): Ge 0.674; Diamond-(Ge): Ge 0.999	experimental	[1] Geng 2011 cites Feschotte 1979	Table 1, p. 2, row 25 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, Ge–Nb system (10)
Phase	Value	T (K)	Class	Source	Location
Nb3Ge	-30.213 kJ/mol (basis unstated)	0	DFT	[2] Utton 2017 cites Papadimitriou 2015 doi	Table 2, p. 6, row 9 report
Nb3Ge	-29.387 kJ/mol (basis unstated)	0	DFT	[2] Utton 2017 cites Papadimitriou 2015 doi	Table 2, p. 6, row 13 report
Nb3Ge	-26.41 kJ/mol (basis unstated)	298.15	model	[2] Utton 2017	Table 2, p. 6, row 14 report
Nb3Ge	-25 kJ/mol (basis unstated)	298.15	model	[2] Utton 2017	Table 2, p. 6, row 10 report
Nb5Ge3	-46.63 kJ/mol (basis unstated)	0	DFT	[2] Utton 2017 cites Papadimitriou 2015 doi	Table 2, p. 6, row 5 report
Nb5Ge3	-46.53 kJ/mol (basis unstated)	0	DFT	[2] Utton 2017 cites Papadimitriou 2015 doi	Table 2, p. 6, row 1 report
Nb5Ge3	-42.892 kJ/mol (basis unstated)	298.15	model	[2] Utton 2017	Table 2, p. 6, row 6 report
Nb5Ge3	-42 kJ/mol (basis unstated)	298.15	model	[2] Utton 2017	Table 2, p. 6, row 2 report
NbGe2	-37.87 kJ/mol (basis unstated)	0	DFT	[2] Utton 2017 cites Papadimitriou 2015 doi	Table 2, p. 6, row 17 report
NbGe2	-33.24 kJ/mol (basis unstated)	298.15	model	[2] Utton 2017	Table 2, p. 6, row 18 report

Other properties

Phase equilibrium (5)

Phase equilibrium, Ge–Nb system
Property	T (K)	Phases / composition	Class	Source	Location
Phase assemblage		Nb3Ge2 alloy: Nb 0.6	experimental	[1] Geng 2011 cites Kloska 1984 doi	Table 3, p. 3, row 4 report
Phase assemblage		Nb3Ge2 alloy: Nb 0.6	experimental	[1] Geng 2011 cites Pan 1970	Table 3, p. 3, row 1 report
Phase assemblage		Nb3Ge2 alloy: Nb 0.6	experimental	[1] Geng 2011 cites Iijima 1979 doi	Table 3, p. 3, row 3 report
Phase assemblage		Nb3Ge2 alloy: Nb 0.6	model	[1] Geng 2011	Table 3, p. 3, row 6 report
Phase assemblage	1373.15	Nb3Ge2 alloy: Nb 0.6	experimental	[1] Geng 2011 cites Richter 2001 doi	Table 3, p. 3, row 5 report

Sources

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

Tai Geng, Changrong Li, Zhenmin Du, Cuiping Guo, Xinqing Zhao, Huibin Xu, Thermodynamic assessment of the Nb–Ge system, Journal of Alloys and Compounds 509, 3080-3088 (2011). doi:10.1016/j.jallcom.2010.12.005
Claire A. Utton, Ioannis Papadimitriou, Hajime Kinoshita, Panos Tsakiropoulos, Experimental and thermodynamic assessment of the Ge-Nb-Si ternary phase diagram, Journal of Alloys and Compounds 717, 303-316 (2017). doi:10.1016/j.jallcom.2017.04.279

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}
}