Nd–O system

19 accepted literature values from 1 paper(s) (experimental 12, model 7); 2 calculated phase diagram(s).

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (10) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	12
model	7

Accepted values by property group
Property group	Values
phase transition	14
formation	1
heat capacity / entropy / enthalpy	1
crystal structure	3

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
NdO-07Zin.tdb	M. Zinkevich, Prog. Mater. Sci., 52, 597-647(2007). doi:10.1016/j.pmatsci.2006.09.002	`0671e946c589d9b94db9de71b22e6f955c5c0d3ee76a1f9156ef1065d6e044da`	viewer · TDB · JSON
NdO-15Dot.tdb	G. Dottavio, Y. Pontillon, L. Desgranges, C. Gueneau, R.C. Belin, J. Nucl. Mater., 458, 394-405(2015). doi:10.1016/j.jnucmat.2014.12.061	`cbc54824da87bc68adb0c2ab2e9bdbffffff54a065ce55885a75736f27ead472`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
NdO-15Dot.tdb	1305.26	ION (x(O) 0.00973) + BCC_A2 (x(O) 0.01477) + A_R2O3_D52 (x(O) 0.6)

Convex hulls: Materials Project DFT hull · OQMD DFT hull

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, Nd–O system (1)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location	Quote
A-Nd2O3	Nd2O3	-361.38 kJ/mol-atom	298.15	model	-364.863 (mp-aaaaabof)	-349.317 (oqmd-30801)	[1] ZINKEVICH 2007	Table 6.1, p. 24, row 31 report

Other properties

Phase transition (14)

Phase transition, Nd–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Phase transition	2333 K	2333	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Shevtchenko 1985	Table 2.1, p. 6, row 37 report
Phase transition	2340 K	2340	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Adylov 1987	Table 2.1, p. 6, row 41 report
Phase transition	2373 K	2373	polymorphic: A <=> H alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 2.2, p. 8, row 13 report
Phase transition	2373 K	2373	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Coutures 1976	Table 2.1, p. 6, row 33 report
Phase transition	2373 K	2373	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Coutures 1985	Table 2.1, p. 6, row 39 report
Phase transition	2373 K	2373	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Foex 1966	Table 2.1, p. 6, row 31 report
Phase transition	2373 K	2373	polymorphic: A ⟺ H alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Tresvyatkii 1971	Table 2.1, p. 6, row 35 report
Phase transition	2435 K	2435	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Adylov 1987	Table 2.1, p. 6, row 42 report
Phase transition	2453 K	2453	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Shevtchenko 1985	Table 2.1, p. 6, row 38 report
Phase transition	2473 K	2473	polymorphic: H <=> X alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 2.2, p. 8, row 27 report
Phase transition	2473 K	2473	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Tresvyatkii 1971	Table 2.1, p. 6, row 36 report
Phase transition	2473 K	2473	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Coutures 1985	Table 2.1, p. 6, row 40 report
Phase transition	2473 K	2473	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Coutures 1976	Table 2.1, p. 6, row 34 report
Phase transition	2473 K	2473	polymorphic: H ⟺ X alloy: Nd 0.4, O 0.6	experimental	[1] ZINKEVICH 2007 cites Foex 1966	Table 2.1, p. 6, row 32 report

Heat capacity / entropy / enthalpy (1)

Heat capacity / entropy / enthalpy, Nd–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Entropy printed: °S	157.89 unknown	298.15	A-Nd2O3 alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 6.1, p. 24, row 31 report

Crystal structure (3)

Crystal structure, Nd–O system
Property	Value	T (K)	Phases / composition	Class	Source	Location
lattice molar volume	45.893 cm3 mol-1	298.15	Nd2O3 (A-type) alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 3.1, p. 12, row 6 report
lattice molar volume	46.796 cm3 mol-1	298.15	Nd2O3 (B-type) alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 3.1, p. 12, row 6 report
lattice molar volume	51.198 cm3 mol-1	298.15	Nd2O3 (C-type) alloy: Nd 0.4, O 0.6	model	[1] ZINKEVICH 2007	Table 3.1, p. 12, row 6 report

Sources

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

M ZINKEVICH, Thermodynamics of rare earth sesquioxides, Progress in Materials Science 52, 597-647 (2007). doi:10.1016/j.pmatsci.2006.09.002

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}
}