Ge–O system

30 accepted literature values from 1 paper(s) (experimental 18, model 9, unspecified 3); 2 calculated phase diagram(s). 8 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 (10) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	18
model	9
unspecified	3

Accepted values by property group
Property group	Values
invariant reaction	2
phase transition	4
formation	14
heat capacity / entropy / enthalpy	9
other property	1

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
GeO-15Din.tdb	A.T. Dinsdale, A. Akhmetova, A.V. Khvan, N. Aristova, J. Phase Equilib. Diffus., 36, 254-61(2015). doi:10.1007/s11669-015-0379-1	`004d6c7cf629014a386794c6bee28f4648f67db68a6637c066d4e70afa63d0ed`	viewer · TDB · JSON
GeO-21Baj-3g.tdb	I. Bajenova, A. Khvan, M. Derevyanko, N. Aristova, A. Dinsdale, A. Kondriatev, A. Pisch, Calphad, 74, 102299(2021). doi:10.1016/j.calphad.2021.102299	`904325ae56bbb509f886d3d920b843a6c2e15e9e530a7f6f10c32ab793adce67`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
GeO-15Din.tdb	1207.81	DIAMOND_A4 (x(O) 0) + ION#2 (x(O) 0.0117) + ION (x(O) 0.57976)
GeO-21Baj-3g.tdb	1389.19	GEO2_HT (x(O) 0.66667) + ION (x(O) 0.66667) + GAS (x(O) 1)
GeO-21Baj-3g.tdb	1207.81	DIAMOND_A4 (x(O) 0) + ION#2 (x(O) 0.0117) + ION (x(O) 0.57976)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull GeO-15Din

Invariant reactions (literature)

Invariant reactions reported in the literature for the Ge–O system (2)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location	Quote
1185	eutectic		experimental	[1] Dinsdale 2015	p. 1 report	Measurements carried out by Trumbore et al. indicate that the stable eutectic involving the lower temperature tetragonal phase should be at 1185 K.
1143	eutectic		experimental	[1] Dinsdale 2015 cites Candidus 1955 doi	p. 1 report	Candidus and Tuomi[29] measured the eutectic temperature involving crystalline Ge and GeO2 to be 1143 K.

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–O system (14)
Phase	Value	T (K)	Class	Source	Location
GeO2 hexagonal	-574 kJ/mol (basis unstated)	298.15	experimental	[1] Dinsdale 2015 cites Katayama 1975	Table 4, p. 4, row 10 report
GeO2 hexagonal	-556.5 kJ/mol (basis unstated) ± 2	298.15	model	[1] Dinsdale 2015 cites Faktor 1965 doi	Table 4, p. 4, row 8 report
GeO2 hexagonal	-556.1 kJ/mol (basis unstated) ± 2	298.15	model	[1] Dinsdale 2015	Table 4, p. 4, row 14 report
GeO2 hexagonal	-556 kJ/mol (basis unstated) ± 8	298.15	experimental	[1] Dinsdale 2015 cites Jolly 1952 doi	Table 4, p. 4, row 3 report
GeO2 hexagonal	-556 kJ/mol (basis unstated) ± 5	298.15	experimental	[1] Dinsdale 2015 cites Yokokawa 1957 doi	Table 4, p. 4, row 4 report
GeO2 hexagonal	-555.4 kJ/mol (basis unstated) ± 2	298.15	experimental	[1] Dinsdale 2015 cites Yokokawa 1957 doi	Table 4, p. 4, row 5 report
GeO2 hexagonal	-554.7 kJ/mol (basis unstated) ± 1	298.15	experimental	[1] Dinsdale 2015 cites Gross 1966 doi	Table 4, p. 4, row 9 report
GeO2 hexagonal	-554.7 kJ/mol (basis unstated) ± 1	298.15	experimental	[1] Dinsdale 2015 cites Katayama 1975	Table 4, p. 4, row 11 report
GeO2 hexagonal	-554.7 kJ/mol (basis unstated) ± 1	298.15	model	[1] Dinsdale 2015 cites Gurvich 1990	Table 4, p. 4, row 12 report
GeO2 hexagonal	-553.82 kJ/mol (basis unstated)	298.15	model	[1] Dinsdale 2015 cites Richet 1990 doi	Table 4, p. 4, row 13 report
GeO2 hexagonal	-553 kJ/mol (basis unstated) ± 5	298.15	experimental	[1] Dinsdale 2015 cites Bills 1964 doi	Table 4, p. 4, row 7 report
GeO2 hexagonal	-540.1 kJ/mol (basis unstated)	298.15	experimental	[1] Dinsdale 2015 cites Mah 1962	Table 4, p. 4, row 6 report
GeO2 hexagonal	-538 kJ/mol (basis unstated)	298.15	experimental	[1] Dinsdale 2015 cites Hahn 1940 doi	Table 4, p. 4, row 2 report
GeO2 hexagonal	-536 kJ/mol (basis unstated)	298.15	experimental	[1] Dinsdale 2015 cites Becker 1932 doi	Table 4, p. 4, row 1 report

Other properties

Phase transition (4)

Phase transition, Ge–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	1308 K	1308	polymorphic: tet → hex alloy: O 0.666667	unspecified	[1] Dinsdale 2015	Table 6, p. 5, row 4 report
Phase transition	1342.3 K	1342.3	congruent transformation: tet → liq alloy: O 0.666667	unspecified	[1] Dinsdale 2015	Table 6, p. 5, row 6 report
Phase transition	1359 K	1359	tetragonal GeO2	experimental	[1] Dinsdale 2015 cites Laubengayer 1932	p. 2 report	The metastable melting point of tetragonal GeO2 was reported to be 1359 ± 5 K by Laubengayer and Morton.[8]
Phase transition	1388 K	1388	congruent transformation: hex → liq alloy: O 0.666667	unspecified	[1] Dinsdale 2015	Table 6, p. 5, row 5 report

Heat capacity / entropy / enthalpy (9)

Heat capacity / entropy / enthalpy, Ge–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S298.15 (3rd law)	57.279 J/mol (basis unstated)/K	298.15	hexagonal GeO2 alloy: O 0.666667	model	[1] Dinsdale 2015	Table 5, p. 4, row 2 report
Entropy printed: S298.15 (3rd law)	55.27 J/mol (basis unstated)/K ± 0.4	298.15	hexagonal GeO2 alloy: O 0.666667	experimental	[1] Dinsdale 2015 cites King 1958 doi	Table 5, p. 4, row 1 report
Entropy printed: S298.15	40.58 unknown ± 2.9	298.15	tetragonal GeO2 alloy: O 0.666667	model	[1] Dinsdale 2015 cites Gurvich 1990	Table 2, p. 3, row 5 report
Entropy printed: S298.15 (3rd law)	32.4 unknown ± 1.6	298.15	tetragonal GeO2 alloy: O 0.666667	experimental	[1] Dinsdale 2015 cites Counsell 1967	Table 2, p. 3, row 4 report
Entropy printed: S298.15	39.71 unknown ± 0.1	298.15	tetragonal GeO2 alloy: O 0.666667	model	[1] Dinsdale 2015 cites Richet 1990 doi	Table 2, p. 3, row 6 report
Entropy printed: S298.15	39.71 unknown ± 0.13	298.15	tetragonal GeO2 alloy: O 0.666667	model	[1] Dinsdale 2015	Table 2, p. 3, row 7 report
Entropy printed: S298.15 (3rd law)	39.3 unknown ± 1.6	298.15	tetragonal GeO2 alloy: O 0.666667	experimental	[1] Dinsdale 2015 cites Yu 1968	Table 2, p. 3, row 2 report
Entropy printed: S298.15 (2nd law)	36.2 unknown ± 12	298.15	tetragonal GeO2 alloy: O 0.666667	model	[1] Dinsdale 2015 cites Newns 1966	Table 2, p. 3, row 3 report
Entropy printed: S298.15 (2nd law)	31.1 unknown ± 10	298.15	tetragonal GeO2 alloy: O 0.666667	experimental	[1] Dinsdale 2015 cites Faktor 1965 doi	Table 2, p. 3, row 1 report

Other property (1)

Other property, Ge–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Other printed: enthalpy of fusion	17.15 kJ/mol	1388		experimental	[1] Dinsdale 2015 cites Newns 1966	p. 3 report	The enthalpy of fusion of the hexagonal form (17.15 kJ/mol) at the melting point (1388 K) has been obtained by Newns and Hanks[11] using a differential thermal analysis technique.

Sources

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

A. T. Dinsdale, A. Akhmetova, A. V. Khvan, N. Aristova, A Critical Assessment of Thermodynamic and Phase Diagram Data for the Ge-O System, J. Phase Equilib. Diffus. 36, 254-261 (2015). doi:10.1007/s11669-015-0379-1

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}
}