CoCr: enthalpy of formation

1 accepted literature formation-enthalpy value(s) (experimental 1); experimental median 6.77 kJ/mol-atom (n = 1); Materials Project 14.816 kJ/mol-atom (mp-aaacfmex); OQMD 2.922 kJ/mol-atom (oqmd-1484947).

Systems: Co–Cr

Literature values

Enthalpy of formation of CoCr reported in the literature (1)
ValuePhase as printedT (K)ClassMethodSystemSourceLocationQuote
6.77 kJ/mol-atomCoCr473experimentalCo–Cr[1] Liu 2015
cites ref. 67
p. 9
report
However, Downie and Arslan [67] measured the formation enthalpy of one σCoCr sample close to the composition of the end-member σ-(Co)8(Cr)18(Cr)4 at 473 K and found ΔfH = 6.77 kJ/mol-atom.

Uncertainty budget

Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.

Uncertainty budget of the literature values of CoCr
ValueUnitPrintedReadingMethod (class, basis)CompositionScatterConversionEffective
6.77kJ/mol-atom0.0053.5 (unknown, calibrated)3.5

DFT formation energies

Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.

DFT formation energy of CoCr
SourceEntrykJ/mol-atomeV/atomSpace groupE above hull (kJ/mol-atom)E above hull (eV/atom)Theoretical
Materials Projectmp-aaacfmex14.8160.153561Pm-3m14.81630.1536yes
OQMDoqmd-14849472.9220.030289P4/mmm3.48220.0361yes

DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. doi:10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. doi:10.1007/s11837-013-0755-4 (CC BY 4.0);

Sources

  1. Xuan L. Liu, Thomas Gheno, Bonnie B. Lindahl, Greta Lindwall, Brian Gleeson, Zi-Kui Liu, First-Principles Calculations, Experimental Study, and Thermodynamic Modeling of the Al-Co-Cr System, PLoS ONE 10, e0121386 (2015). doi:10.1371/journal.pone.0121386