Fe2Nb: enthalpy of formation

9 accepted literature formation-enthalpy value(s) (experimental 2, model 7).

Literature values

Enthalpy of formation of Fe2Nb reported in the literature (9)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-23.7 kJ/mol (basis unstated)	Fe0.6667Nb0.3333	1200	experimental	emf	Fe–Nb	[1] Toffolon 2000 cites ref. 69	Table I, p. 2, row 2 report
-20.5 kJ/mol (basis unstated)	Fe0.6667Nb0.3333	1250	experimental	emf	Fe–Nb	[1] Toffolon 2000 cites ref. 66	Table I, p. 2, row 1 report
-23.67 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000	Table I, p. 2, row 9 report
-23.41 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 94	Table I, p. 2, row 8 report
-22.5 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 67	Table I, p. 2, row 3 report
-21 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 77	Table I, p. 2, row 5 report
-17.9 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 72	Table I, p. 2, row 4 report
-17.87 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 90	Table I, p. 2, row 6 report
-12.24 kJ/mol (basis unstated)	Fe0.6667Nb0.3333		model		Fe–Nb	[1] Toffolon 2000 cites ref. 93	Table I, p. 2, row 7 report

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 Fe2Nb
Value	Unit	Reading	Method (class, basis)	Effective
-23.7	kJ/mol (basis unstated)	0.05	4.6 (emf, cleaned_below_threshold)	4.6
-20.5	kJ/mol (basis unstated)	0.05	4.6 (emf, cleaned_below_threshold)	4.6
-23.67	kJ/mol (basis unstated)	0.005	3.9 (model_calculated, calibrated)	3.9
-23.41	kJ/mol (basis unstated)	0.005	3.9 (model_calculated, calibrated)	3.9
-22.5	kJ/mol (basis unstated)	0.05	3.9 (model_calculated, calibrated)	3.9
-21	kJ/mol (basis unstated)	0.05	3.9 (model_calculated, calibrated)	3.9
-17.9	kJ/mol (basis unstated)	0.05	3.9 (model_calculated, calibrated)	3.9
-17.87	kJ/mol (basis unstated)	0.005	3.9 (model_calculated, calibrated)	3.9
-12.24	kJ/mol (basis unstated)	0.005	3.9 (model_calculated, calibrated)	3.9

Sources

C. Toffolon, C. Servant, Thermodynamic assessment of the Fe-Nb system, Calphad 24, 97-112 (2000). doi:10.1016/s0364-5916(00)00017-1

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-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735943
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); 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); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; 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. 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_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  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}
}