Co system

26 accepted literature values from 12 paper(s) (experimental 7, model 13, DFT 4, unspecified 2); 0 calculated phase diagram(s).

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Accepted values by evidence class
Evidence class	Values
experimental	7
model	13
DFT	4
unspecified	2

Accepted values by property group
Property group	Values
invariant reaction	8
phase transition	2
formation	3
mixing / partial	3
activity / EMF / Gibbs energy	1
crystal structure	9

Invariant reactions (literature)

Invariant reactions reported in the literature for the Co system (8)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1768	congruent melting: Co(FCC) <-> Co(L)	Co(FCC):	unspecified	[1] Vassilev 2004 cites Dinsdale 1991	Table 3, p. 6, row 1 report
695.15	polymorphic: αCo ↔ εCo	εCo:	experimental	[2] Liu 2008 cites Okamoto 2000	Table 2, p. 4, row 21 report
695.15	polymorphic: αCo -> εCo	εCo:	model	[3] Ansara 1991	Table 1, p. 5, row 13 report
695	polymorphic: (αCo) ↔ (εCo)		unspecified	[4] Zhang 2008 cites Dudkin 1956	Table 1, p. 2, row 1 report
695	α-Co -> ε-Co	ε-Co:	experimental	[5] Golumbfskie 2006 cites Niessen 1983 doi	Table 2, p. 2, row 2 report
695	α-Co -> ε-Co	ε-Co:	model	[5] Golumbfskie 2006	Table 2, p. 2, row 1 report
695	polymorphic: (αCo) ↔ (εCo)		model	[4] Zhang 2008	Table 1, p. 2, row 2 report
694.15	polymorphic: αCo ↔ εCo	εCo:	model	[2] Liu 2008	Table 2, p. 4, row 22 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 system (3)
Phase	Value	Class	Source	Location
m-(Co,Fe)4Al13	-40.44 kJ/mol-atom	DFT	[6] Ostrowska 2019 cites Shevchenko 2014 doi	Table 2, p. 2, row 6 report
m-(Co,Fe)4Al13	-37.64 kJ/mol-atom	DFT	[6] Ostrowska 2019 cites AFLOW	Table 2, p. 2, row 7 report
m-(Co,Fe)4Al13	-37.26 kJ/mol-atom	DFT	[6] Ostrowska 2019 cites materialsproject	Table 2, p. 2, row 5 report

Other properties

Phase transition (2)

Phase transition, Co system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	695 K	695	ε-Co + α-Co	model	[7] Chen 2003 cites Dinsdale 2003	p. 1 report	␧-Co (hcp) is stable up to 695 K, at which temperature it transforms to ␣-Co (fcc) [1991Din].
Phase transition	1150 K	1150	magnetic	experimental	[8] Davydov 1999 cites Takayama 1981 doi	p. 2 report	Using x-ray diffraction (XRD) and microprobe analysis, [81Tak] detected an abrupt change in the fcc (Co) solvus line at about 1150 K and showed that this anomaly is caused by the magnetic transformation in this phase.

Mixing / partial (3)

Mixing / partial, Co system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Enthalpy of mixing printed: ΔH^E	0 kJ/mol (basis unstated)	1810.15	liquid alloy: Co 1	experimental	[9] Kubišta 2000	Table 4, p. 4, row 1 report
Entropy of mixing printed: ΔS^E	0 J/mol (basis unstated)/K	1810.15	liquid alloy: Co 1	experimental	[9] Kubišta 2000	Table 4, p. 4, row 1 report
Gibbs energy of mixing printed: ΔG^E	0 kJ/mol (basis unstated)	1810.15	liquid alloy: Co 1	experimental	[9] Kubišta 2000	Table 4, p. 4, row 1 report

Activity / EMF / Gibbs energy (1)

Activity / EMF / Gibbs energy, Co system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Gibbs energy printed: ΔG°	-98862 J/mol	1873	liquid Co	experimental	[7] Chen 2003 cites Fischer 1971	Table 7, p. 11, row 4 report

Crystal structure (9)

Crystal structure, Co system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	3.545 Å		fcc alloy: Co 1	model	[10] Kim 2011	Table 1, p. 2, row 3 report
Lattice a	3.518 Å		fcc alloy: Co 1	model	[10] Kim 2011	Table 1, p. 2, row 2 report
Lattice a	3.501 Å		fcc alloy: Co 1	model	[10] Kim 2011	Table 1, p. 2, row 1 report
Lattice a	3.544 Å	298.15	αCo	model	[11] Cacciamani 2000 cites Villars 1991	Table 1, p. 2, row 2 report
Lattice a	2.507 Å	298.15	εCo	model	[11] Cacciamani 2000 cites Villars 1991	Table 1, p. 2, row 1 report
Lattice a	2.505 Å	298.15	εCo	model	[11] Cacciamani 2000 cites Villars 1991	Table 1, p. 2, row 1 report
Lattice c	4.089 Å	298.15	εCo	model	[11] Cacciamani 2000 cites Villars 1991	Table 1, p. 2, row 1 report
Lattice c	4.07 Å	298.15	εCo	model	[11] Cacciamani 2000 cites Villars 1991	Table 1, p. 2, row 1 report
Molar volume printed: V0	10.82 Å3/atom	0	hcp(Co)	DFT	[12] Zhou 2020	Table V, p. 12, row 1 report

Sources

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

George Penev Vassilev, Min Jiang, Thermodynamic Optimization of the Co-Zn System, Journal of Phase Equilibria & Diffusion 25, 259-268 (2004). doi:10.1361/15477030419522
X.J. Liu, P. Yu, C.P. Wang, K. Ishida, Thermodynamic evaluation of the Co–Sc and Fe–Sc systems, Journal of Alloys and Compounds 466, 169-175 (2008). doi:10.1016/j.jallcom.2007.11.069
I Ansara, F Ajersch, The Ga-Pb (Gallium-Lead) System, JPE 12, 73-77 (1991). doi:10.1007/bf02663678
Yubi Zhang, Changrong Li, Zhenmin Du, Tai Geng, The thermodynamic assessment of the Co–Sb system, Calphad 32, 56-63 (2008). doi:10.1016/j.calphad.2007.11.001
William Golumbfskie, Zi-Kui Liu, CALPHAD/first-principles re-modeling of the Co–Y binary system, Journal of Alloys and Compounds 407, 193-200 (2006). doi:10.1016/j.jallcom.2005.06.037
Marlena Ostrowska, Gabriele Cacciamani, Critical evaluation and thermodynamic modeling of the Al-Co-Fe system, Journal of Alloys and Compounds 794, 553-568 (2019). doi:10.1016/j.jallcom.2019.04.170
Ming Chen, Bengt Hallstedt, Ludwig J. Gauckler, Thermodynamic assessment of the Co-O system, JPE 24, 212-227 (2003). doi:10.1361/105497103770330514
A. Davydov, U. R. Kattner, Thermodynamic assessment of the Co-Mo system, JPE 20, 5-16 (1999). doi:10.1361/105497199770335893
Jaroslav Kubišta, Jan Vřešt’ál, Thermodynamics of the liquid Co-Cu system and calculation of phase diagram, JPE 21, 125-129 (2000). doi:10.1361/105497100770340165
DongEung Kim, James E. Saal, Liangcai Zhou, ShunLi Shang, Yong Du, Zi-Kui Liu, Thermodynamic modeling of fcc order/disorder transformations in the Co–Pt system, Calphad 35, 323-330 (2011). doi:10.1016/j.calphad.2011.04.005
G. Cacciamani, R. Ferro, I. Ansara, N. Dupin, Thermodynamic modelling of the Co–Ti system, Intermetallics 8, 213-222 (2000). doi:10.1016/s0966-9795(99)00098-9
Chenyang Zhou, Cuiping Guo, Jingbo Li, Changrong Li, Zhenmin Du, Key Experiments and Thermodynamic Description of the Co-Nb-Ni System, Metall Mater Trans A 51, 5892-5911 (2020). doi:10.1007/s11661-020-05963-2

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 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_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}
}