Co–O system

120 accepted literature values from 1 paper(s) (experimental 91, model 29); 1 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	91
model	29

Accepted values by property group
Property group	Values
invariant reaction	19
phase transition	10
formation	10
heat capacity / entropy / enthalpy	8
model expression	73

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
CoO-03Che-LB.tdb	M. Chen, B. Hallstedt, L.J. Gauckler, J. Phase Equilib., 24, 212-27(2003). doi:10.1361/105497103770330514	`6da44079fa3d4ae1ab1d1023b514c1f899ec754ee50223c5c3dc2084aff2fa64`	viewer · TDB · JSON

Convex hulls: Materials Project DFT hull · OQMD DFT hull

Invariant reactions (literature)

Invariant reactions reported in the literature for the Co–O system (19)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location	Quote
2208	congruent melting: L2 -> CoO	L2: Co 0.5, O 0.5; CoO: Co 0.5, O 0.5	experimental	[1] Chen 2003 cites H 1931	Table 8, p. 12, row 7 report
2103	congruent melting: L2 -> CoO	L2: Co 0.5, O 0.5; CoO: Co 0.5, O 0.5	experimental	[1] Chen 2003 cites Chase 1985	Table 8, p. 12, row 9 report
2097	congruent melting: L2 -> CoO	L2: Co 0.5, O 0.5; CoO: Co 0.5, O 0.5	model	[1] Chen 2003	Table 8, p. 12, row 10 report
2083	congruent melting: L2 -> CoO	L2: Co 0.5, O 0.5; CoO: Co 0.5, O 0.5	experimental	[1] Chen 2003 cites H 1932	Table 8, p. 12, row 8 report
1766	eutectic: L1 -> Co(fcc) + CoO	L1: O 0.0044	model	[1] Chen 2003	Table 8, p. 12, row 6 report
1763	eutectic		experimental	[1] Chen 2003 cites Jacob 1985	p. 1 report	The most recently determined Co-CoO eutectic point, by Jacob and Hajra [1985Jac], is at T ⳱ 1763 K and xO ⳱ 0.0048.
1763	eutectic: L1 -> Co(fcc) + CoO	L1: O 0.0048	experimental	[1] Chen 2003 cites Jacob 1985	Table 8, p. 12, row 5 report
1730	eutectic: L1 -> Co(fcc) + CoO		experimental	[1] Chen 2003 cites Taskinen 1983	Table 8, p. 12, row 4 report
1730	eutectic		experimental	[1] Chen 2003 cites Taskinen 1983	p. 1 report	Based on electromotive force (EMF) measurements of the equilibria of Co(s)CoO(s) and Co(l)-CoO(s), Kemori et al. [1977Kem] determined the eutectic temperature of Co-CoO as 1727 K while Taskinen [1983Tas] gave a value of 1730 K.
1727	eutectic		experimental	[1] Chen 2003 cites Kemori 1977 doi	p. 1 report	Based on electromotive force (EMF) measurements of the equilibria of Co(s)CoO(s) and Co(l)-CoO(s), Kemori et al. [1977Kem] determined the eutectic temperature of Co-CoO as 1727 K while Taskinen [1983Tas] gave a value of 1730 K.
1727	eutectic: L1 -> Co(fcc) + CoO		experimental	[1] Chen 2003 cites Kemori 1977 doi	Table 8, p. 12, row 3 report
1724	eutectic: L1 -> Co(fcc) + CoO	L1: O 0.0084	experimental	[1] Chen 2003 cites Hansen 1958	Table 8, p. 12, row 2 report
1719	eutectic: L1 -> Co(fcc) + CoO	L1: O 0.0095	experimental	[1] Chen 2003 cites ref. 1951Aa	Table 8, p. 12, row 1 report
1719	eutectic		experimental	[1] Chen 2003 cites Asanti 1951 doi	p. 1 report	Asanti and Kohlmeyer [1951Asa] measured the eutectic of Co-CoO and determined the eutectic point to be at approximately T ⳱ 1719 K and xO ⳱ 0.0095.
1233	3CoO + 0.5O2 -> Co3O4 (in 1 bar O2)	Co3O4: Co 0.428571, O 0.571429	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 8, p. 12, row 14 report
1224	3CoO + 0.5O2 -> Co3O4 (in 1 bar O2)	Co3O4: Co 0.428571, O 0.571429	model	[1] Chen 2003	Table 8, p. 12, row 15 report
1173	3CoO + 0.5O2 -> Co3O4 (in air)	Co3O4: Co 0.428571, O 0.571429	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 8, p. 12, row 12 report
1170	3CoO + 0.5O2 -> Co3O4 (in air)	Co3O4: Co 0.428571, O 0.571429	experimental	[1] Chen 2003 cites Sreedharan 1977	Table 8, p. 12, row 11 report
1170	3CoO + 0.5O2 -> Co3O4 (in air)	Co3O4: Co 0.428571, O 0.571429	model	[1] Chen 2003	Table 8, p. 12, row 13 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, Co–O system (10)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location
Co3O4	Co3O4	-130.77 kJ/mol-atom	298.15	model	-125.536 (mp-aaacujjd)	-129.587 (oqmd-4562)	[1] Chen 2003	Table 5, p. 10, row 7 report
Co3O4	Co3O4	-130 kJ/mol-atom	298.15	model	-125.536 (mp-aaacujjd)	-129.587 (oqmd-4562)	[1] Chen 2003 cites Chase 1985	Table 5, p. 10, row 6 report
Co3O4	Co3O4	-127.286 kJ/mol-atom	298.15	model	-125.536 (mp-aaacujjd)	-129.587 (oqmd-4562)	[1] Chen 2003 cites Wagman 1969	Table 5, p. 10, row 4 report
CoO	CoO	-120.29 kJ/mol-atom	298.15	experimental	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Mixter 1910 doi	Table 5, p. 10, row 1 report
CoO	CoO	-120.29 kJ/mol-atom	298.15	experimental	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Roth 1931 doi	Table 5, p. 10, row 2 report
CoO	CoO	-119.45 kJ/mol-atom	298.15	experimental	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Boyle 1954 doi	Table 5, p. 10, row 3 report
CoO	CoO	-118.97 kJ/mol-atom	298.15	model	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Wagman 1969	Table 5, p. 10, row 4 report
CoO	CoO	-118.85 kJ/mol-atom	298.15	model	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Chase 1985	Table 5, p. 10, row 6 report
CoO	CoO	-118.75 kJ/mol-atom	298.15	model	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003 cites Cyr 1981 doi	Table 5, p. 10, row 5 report
CoO	CoO	-118.43 kJ/mol-atom	298.15	model	-123.923 (mp-aaaabhdw)	-123.858 (oqmd-2169004)	[1] Chen 2003	Table 5, p. 10, row 7 report

Other properties

Phase transition (10)

Phase transition, Co–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	33 K	33	magnetic	experimental	[1] Chen 2003 cites Chibirova 1984	p. 3 report	Co3O4 has been found to undergo a transition from paramagnetic state to antiferromagnetic state at 40 K [1964Rot] or 33 K [1984Chi].
Phase transition	40 K	40	magnetic	experimental	[1] Chen 2003 cites Roth 1964 doi	p. 3 report	Co3O4 has been found to undergo a transition from paramagnetic state to antiferromagnetic state at 40 K [1964Rot] or 33 K [1984Chi].
Phase transition	290 K	290	magnetic	experimental	[1] Chen 2003 cites Jauch 2003	p. 3 report	At low temperature, CoO is an antiferromagnetic compound with a Néel temperature of TN ≈ 290 K [2001Jau].
Phase transition	695 K	695	hcp + fcc	model	[1] Chen 2003 cites Nishizawa 1983 doi	p. 6 report	In the recent review papers on the thermodynamic properties of cobalt metal [1983Nis, 1987Gui, 1990Mas], the stable temperature range for the hcp phase is below 695 K; the range for the fcc phase is from 695 K up to its melting point.
Phase transition	1170 K	1170	other	experimental	[1] Chen 2003	p. 1 report	Co3O4 decomposes at about 1170 K (in air), and CoO is stable up to its melting point, given as 2083 K [1932War] and 2103 K [1985Cha].
Phase transition	1768 K	1768	α-Co + liquid	experimental	[1] Chen 2003	p. 1 report	The melting point of ␣-Co is 1768 K.
Phase transition	2083 K	2083	congruent melting	experimental	[1] Chen 2003 cites H 1932	p. 1 report	The earliest measurement on the congruent melting point of CoO was done by Wartenberg and Gurr [1931War], giving a value of 2208 K, but it was soon corrected to 2083 K [1932War].
Phase transition	2097 K	2097	congruent transformation	model	[1] Chen 2003	p. 12 report	The calculated congruent melting point of CoO is 2097 K, in reasonable agreement with the JANAF tables [1985Cha].
Phase transition	2103 K	2103	CoO + liquid	experimental	[1] Chen 2003 cites Chase 1985	p. 1 report	The JANAF tables [1985Cha] adopt 2103 ± 10 K as Tfus. for CoO based on the work of Coutures and Foëx [1972Cou].
Phase transition	2208 K	2208	congruent melting	experimental	[1] Chen 2003 cites H 1931	p. 1 report	The earliest measurement on the congruent melting point of CoO was done by Wartenberg and Gurr [1931War], giving a value of 2208 K, but it was soon corrected to 2083 K [1932War].

Heat capacity / entropy / enthalpy (8)

Heat capacity / entropy / enthalpy, Co–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S (Co3O4)	15.6286 J/mol-atom/K	298.15	Co3O4 alloy: O 0.571429	model	[1] Chen 2003	Table 6, p. 10, row 5 report
Entropy printed: S (Co3O4)	15.6143 J/mol-atom/K	298.15	Co3O4 alloy: O 0.571429	experimental	[1] Chen 2003 cites Khriplovich 1982 doi	Table 6, p. 10, row 2 report
Entropy printed: S (Co3O4)	14.6429 J/mol-atom/K	298.15	Co3O4 alloy: O 0.571429	experimental	[1] Chen 2003 cites King 1957 doi	Table 6, p. 10, row 1 report
Entropy printed: S (Co3O4)	16.3271 J/mol-atom/K	298.15	Co3O4 alloy: O 0.571429	model	[1] Chen 2003 cites Chase 1985	Table 6, p. 10, row 4 report
Entropy printed: S (CoO)	27.155 J/mol-atom/K	298.15	CoO alloy: O 0.5	model	[1] Chen 2003	Table 6, p. 10, row 5 report
Entropy printed: S (CoO)	26.415 J/mol-atom/K	298.15	CoO alloy: O 0.5	experimental	[1] Chen 2003 cites Nabutovskaya 1985	Table 6, p. 10, row 3 report
Entropy printed: S (CoO)	26.485 J/mol-atom/K	298.15	CoO alloy: O 0.5	experimental	[1] Chen 2003 cites King 1957 doi	Table 6, p. 10, row 1 report
Entropy printed: S (CoO)	26.4965 J/mol-atom/K	298.15	CoO alloy: O 0.5	model	[1] Chen 2003 cites Chase 1985	Table 6, p. 10, row 4 report

Model expression (73)

Model expression, Co–O system
Property	Value	Phases / composition	Class	Source	Location
gibbs energy expression term printed: ΔG° (coefficient of T)	177.58 J/mol/K	UNKNOWN	model	[1] Chen 2003	Table 3, p. 9, row 27 report
gibbs energy expression term printed: ΔG° (constant term A)	-213459 J/mol	UNKNOWN	model	[1] Chen 2003	Table 3, p. 9, row 27 report
gibbs energy expression term printed: ΔG° (constant term A)	-215413 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Sreedharan 1977	Table 3, p. 9, row 14 report
gibbs energy expression term printed: ΔG° (coefficient of T)	180.15 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Sreedharan 1977	Table 3, p. 9, row 14 report
gibbs energy expression term printed: ΔG° (coefficient of T)	138.616 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1965	Table 3, p. 9, row 8 report
gibbs energy expression term printed: ΔG° (constant term A)	-171251 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1965	Table 3, p. 9, row 8 report
gibbs energy expression term printed: ΔG° (constant term A)	-207759 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 3, p. 9, row 24 report
gibbs energy expression term printed: ΔG° (coefficient of T)	172.606 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 3, p. 9, row 24 report
gibbs energy expression term printed: ΔG° (coefficient of T)	144.197 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Grimsey 1986 doi	Table 3, p. 9, row 23 report
gibbs energy expression term printed: ΔG° (constant term A)	-188824 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Grimsey 1986 doi	Table 3, p. 9, row 23 report
gibbs energy expression term printed: ΔG° (coefficient of T)	130.44 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1985	Table 3, p. 9, row 22 report
gibbs energy expression term printed: ΔG° (constant term A)	-161071 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1985	Table 3, p. 9, row 22 report
gibbs energy expression term printed: ΔG° (constant term A)	-201995 J/mol	UNKNOWN	model	[1] Chen 2003 cites Chase 1985	Table 3, p. 9, row 26 report
gibbs energy expression term printed: ΔG° (coefficient of T)	165.062 J/mol/K	UNKNOWN	model	[1] Chen 2003 cites Chase 1985	Table 3, p. 9, row 26 report
gibbs energy expression term printed: ΔG° (constant term A)	-212713 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1985	Table 3, p. 9, row 21 report
gibbs energy expression term printed: ΔG° (coefficient of T)	175.972 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites ref. 1985	Table 3, p. 9, row 21 report
gibbs energy expression term printed: ΔG° (coefficient of T)	162.545 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Bugden 1970	Table 3, p. 9, row 10 report
gibbs energy expression term printed: ΔG° (constant term A)	-197142 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Bugden 1970	Table 3, p. 9, row 10 report
gibbs energy expression term printed: ΔG° (coefficient of T)	165.433 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Bugden 1970	Table 3, p. 9, row 9 report
gibbs energy expression term printed: ΔG° (constant term A)	-200022 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Bugden 1970	Table 3, p. 9, row 9 report
gibbs energy expression term printed: ΔG° (constant term A)	-169432 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Melnik 1974	Table 3, p. 9, row 12 report
gibbs energy expression term printed: ΔG° (coefficient of T)	137.515 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Melnik 1974	Table 3, p. 9, row 12 report
gibbs energy expression term printed: ΔG° (constant term A)	-191643 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Enoki 1977 doi	Table 3, p. 9, row 13 report
gibbs energy expression term printed: ΔG° (coefficient of T)	153.282 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Enoki 1977 doi	Table 3, p. 9, row 13 report
gibbs energy expression term printed: ΔG° (coefficient of T)	122.668 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Ingraham 1964 doi	Table 3, p. 9, row 6 report
gibbs energy expression term printed: ΔG° (constant term A)	-151244 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Ingraham 1964 doi	Table 3, p. 9, row 6 report
gibbs energy expression term printed: ΔG° (coefficient of T)	129.381 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 3, p. 9, row 25 report
gibbs energy expression term printed: ΔG° (constant term A)	-159324 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Kale 1988 doi	Table 3, p. 9, row 25 report
gibbs energy expression term printed: ΔG° (constant term A)	-108698 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Biltz 1907	Table 3, p. 9, row 1 report
gibbs energy expression term printed: ΔG° (coefficient of T)	85.958 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Biltz 1907	Table 3, p. 9, row 1 report
gibbs energy expression term printed: ΔG° (coefficient of T)	128.332 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Watanabe 1933	Table 3, p. 9, row 3 report
gibbs energy expression term printed: ΔG° (constant term A)	-161074 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Watanabe 1933	Table 3, p. 9, row 3 report
gibbs energy expression term printed: ΔG° (coefficient of T)	140.219 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Narducci 1985 doi	Table 3, p. 9, row 20 report
gibbs energy expression term printed: ΔG° (constant term A)	-172172 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Narducci 1985 doi	Table 3, p. 9, row 20 report
gibbs energy expression term printed: ΔG° (constant term A)	-165686 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Alcock 1965	Table 3, p. 9, row 7 report
gibbs energy expression term printed: ΔG° (coefficient of T)	135.771 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Alcock 1965	Table 3, p. 9, row 7 report
gibbs energy expression term printed: ΔG° (coefficient of T)	150.334 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Chizhikov 1972	Table 3, p. 9, row 11 report
gibbs energy expression term printed: ΔG° (constant term A)	-179962 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Chizhikov 1972	Table 3, p. 9, row 11 report
gibbs energy expression term printed: ΔG° (coefficient of T)	189.972 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Koumoto 1981 doi	Table 3, p. 9, row 18 report
gibbs energy expression term printed: ΔG° (constant term A)	-223995 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Koumoto 1981 doi	Table 3, p. 9, row 18 report
gibbs energy expression term printed: ΔG° (constant term A)	-147573 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Balakirev 1961	Table 3, p. 9, row 5 report
gibbs energy expression term printed: ΔG° (coefficient of T)	118.051 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Balakirev 1961	Table 3, p. 9, row 5 report
gibbs energy expression term printed: ΔG° (coefficient of T)	147.875 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Flamand 1984	Table 3, p. 9, row 19 report
gibbs energy expression term printed: ΔG° (constant term A)	-181187 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Flamand 1984	Table 3, p. 9, row 19 report
gibbs energy expression term printed: ΔG° (constant term A)	-146890 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Foote 1908 doi	Table 3, p. 9, row 2 report
gibbs energy expression term printed: ΔG° (coefficient of T)	118.266 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Foote 1908 doi	Table 3, p. 9, row 2 report
gibbs energy expression term printed: ΔG° (constant term A)	-122011 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Chufarov 1950	Table 3, p. 9, row 4 report
gibbs energy expression term printed: ΔG° (coefficient of T)	94.855 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Chufarov 1950	Table 3, p. 9, row 4 report
gibbs energy expression term printed: ΔG° (coefficient of T ln T)	-258.981 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Bjorkman 1979	Table 3, p. 9, row 16 report
gibbs energy expression term printed: ΔG° (coefficient of T)	2219.6 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Bjorkman 1979	Table 3, p. 9, row 16 report
gibbs energy expression term printed: ΔG° (constant term A)	-463419 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Bjorkman 1979	Table 3, p. 9, row 16 report
gibbs energy expression term printed: ΔG° (coefficient of T)	140.226 J/mol/K	UNKNOWN	model	[1] Chen 2003	Table 3, p. 9, row 28 report
gibbs energy expression term printed: ΔG° (constant term A)	-171649 J/mol	UNKNOWN	model	[1] Chen 2003	Table 3, p. 9, row 28 report
gibbs energy expression term printed: ΔG° (constant term A)	-167564 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Sreedharan 1977	Table 3, p. 9, row 15 report
gibbs energy expression term printed: ΔG° (coefficient of T)	77.593 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Sreedharan 1977	Table 3, p. 9, row 15 report
gibbs energy expression term printed: ΔG° (constant term A)	-165220 J/mol	UNKNOWN	experimental	[1] Chen 2003 cites Oppermann 1980 doi	Table 3, p. 9, row 17 report
gibbs energy expression term printed: ΔG° (coefficient of T)	135.851 J/mol/K	UNKNOWN	experimental	[1] Chen 2003 cites Oppermann 1980 doi	Table 3, p. 9, row 17 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-61504.8 J/mol	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Tankins 1964	Table 7, p. 11, row 1 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-20.489 J/mol/K	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Tankins 1964	Table 7, p. 11, row 1 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-0.326 J/mol/K	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Fischer 1966 doi	Table 7, p. 11, row 2 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-98240 J/mol	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Fischer 1966 doi	Table 7, p. 11, row 2 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-61630 J/mol	liquid Co alloy: O 0	model	[1] Chen 2003 cites Sigworth 1976 doi	Table 7, p. 11, row 6 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-20.493 J/mol/K	liquid Co alloy: O 0	model	[1] Chen 2003 cites Sigworth 1976 doi	Table 7, p. 11, row 6 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-90984 J/mol	liquid Co alloy: O 0	model	[1] Chen 2003	Table 7, p. 11, row 9 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-4.292 J/mol/K	liquid Co alloy: O 0	model	[1] Chen 2003	Table 7, p. 11, row 9 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-16.681 J/mol/K	liquid Co alloy: O 0	model	[1] Chen 2003 cites Chiang 1976 doi	Table 7, p. 11, row 5 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-67613 J/mol	liquid Co alloy: O 0	model	[1] Chen 2003 cites Chiang 1976 doi	Table 7, p. 11, row 5 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-72467 J/mol	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Belov 1967	Table 7, p. 11, row 3 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-13.086 J/mol/K	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Belov 1967	Table 7, p. 11, row 3 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-7.555 J/mol/K	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Jacob 1985	Table 7, p. 11, row 8 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-84935 J/mol	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Jacob 1985	Table 7, p. 11, row 8 report
gibbs energy expression term printed: ΔG° (coefficient B of A + B·T)	-4.181 J/mol/K	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Janke 1978	Table 7, p. 11, row 7 report
gibbs energy expression term printed: ΔG° (constant term A of A + B·T)	-91335 J/mol	liquid Co alloy: O 0	experimental	[1] Chen 2003 cites Janke 1978	Table 7, p. 11, row 7 report

Sources

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

Ming Chen, Bengt Hallstedt, Ludwig J. Gauckler, Thermodynamic assessment of the Co-O system, JPE 24, 212-227 (2003). doi:10.1361/105497103770330514

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}
}