Nb–Zr system

30 accepted literature values from 2 paper(s) (experimental 10, DFT 20); 2 calculated phase diagram(s). 3 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 (7) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	10
DFT	20

Accepted values by property group
Property group	Values
formation	8
crystal structure	22

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
NbZr-19Laf.tdb	P. Lafaye, C. Toffolon-Masclet, J.-C. Crivello, J.-M. Joubert, Calphad, 64, 43-54(2019). doi:10.1016/j.calphad.2018.11.002	`a42c533c5325c0288ad28d131e2d892bedae12ca11d5d4fdcb42b5ed2fde5084`	viewer · TDB · JSON
NbZr-91Fer-LB.tdb	A. Fernandez Guillermet, Z. Metallkd., 82, 478-87(1991). doi:10.1515/ijmr-1991-820609	`7909b901df4293efe425cce3dc4eee3f1e0e2f69889b11ff43bbee64eef83ff1`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
NbZr-19Laf.tdb	870.48	BCC_A2 (x(Zr) 0.075) + BCC_A2#2 (x(Zr) 0.79441) + HCP_A3 (x(Zr) 0.99364)
NbZr-91Fer-LB.tdb	893.02	BCC_A2 (x(Zr) 0.07891) + BCC_A2#2 (x(Zr) 0.81288) + HCP_A3 (x(Zr) 0.99282)

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull NbZr-91Fer-LB

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, Nb–Zr system (8)
Phase	Value	Class	Source	Location
C15	4.63 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 8 report
C15	48.37 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 7 report
C36	3.33 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 33 report
C36	43.77 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 32 report
τ1	7.17 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 62 report
τ1	41.59 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 61 report
τ2	1.61 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 18 report
τ2	41.15 kJ/mol (basis unstated)	DFT	[1] Lu 2017	Table 2, p. 3, row 17 report

Other properties

Crystal structure (22)

Crystal structure, Nb–Zr system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a printed: a	7.85 Å	0	C15 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 8 report
Lattice a printed: a	8.03 Å	0	C15 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 7 report
Lattice a printed: a	5.7 Å	0	C36 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 32 report
Lattice a printed: a	5.59 Å	0	C36 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 33 report
Lattice a printed: a	12.76 Å	0	τ1 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 62 report
Lattice a printed: a	12.48 Å	0	τ1 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 61 report
Lattice a printed: a	5.68 Å	0	τ2 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 17 report
Lattice a printed: a	5.59 Å	0	τ2 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 18 report
Lattice a	3.313 not_printed ± 0.0011	1023.15	α-Nb alloy: Nb 0.18, Zr 0.82	experimental	[2] Dottor 2023	Table 2, p. 5, row 6 report
Lattice a	3.315 not_printed ± 9.000e-4	1023.15	α-Nb alloy: Nb 0.05, Zr 0.95	experimental	[2] Dottor 2023	Table 2, p. 5, row 11 report
Lattice a	3.2334 not_printed ± 6.000e-4	1023.15	α-Zr alloy: Nb 0.01, Zr 0.99	experimental	[2] Dottor 2023	Table 2, p. 5, row 15 report
Lattice a	3.2248 not_printed ± 8.000e-4	1023.15	α-Zr alloy: Nb 0.05, Zr 0.95	experimental	[2] Dottor 2023	Table 2, p. 5, row 10 report
Lattice a	3.3312 not_printed ± 9.000e-4	1073.15	α-Nb alloy: Nb 0.18, Zr 0.82	experimental	[2] Dottor 2023	Table 2, p. 5, row 3 report
Lattice a	3.2534 not_printed ± 0.0014	1073.15	α-Zr alloy: Nb 0.18, Zr 0.82	experimental	[2] Dottor 2023	Table 2, p. 5, row 1 report
Lattice a	4.7839 not_printed ± 0.0018	1073.15	δ-ZrH2-x alloy: Nb 0.18, Zr 0.82	experimental	[2] Dottor 2023	Table 2, p. 5, row 2 report
Lattice c printed: c	18.29 Å	0	C36 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 32 report
Lattice c printed: c	17.89 Å	0	C36 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 33 report
Lattice c printed: c	9.14 Å	0	τ2 alloy: Nb 0.333333, Zr 0.666667	DFT	[1] Lu 2017	Table 2, p. 3, row 17 report
Lattice c printed: c	8.92 Å	0	τ2 alloy: Nb 0.666667, Zr 0.333333	DFT	[1] Lu 2017	Table 2, p. 3, row 18 report
Lattice c	5.15 not_printed ± 0.0017	1023.15	α-Zr alloy: Nb 0.01, Zr 0.99	experimental	[2] Dottor 2023	Table 2, p. 5, row 15 report
Lattice c	5.1375 not_printed ± 0.0025	1023.15	α-Zr alloy: Nb 0.05, Zr 0.95	experimental	[2] Dottor 2023	Table 2, p. 5, row 10 report
Lattice c	5.1122 not_printed ± 0.0024	1073.15	α-Zr alloy: Nb 0.18, Zr 0.82	experimental	[2] Dottor 2023	Table 2, p. 5, row 1 report

Sources

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

Hai-Jin Lu, Nan Zou, Xu-Shan Zhao, Jian-Yun Shen, Xiao-Gang Lu, Yan-Lin He, Thermodynamic investigation of the Zr-Fe-Nb system and its applications, Intermetallics 88, 91-100 (2017). doi:10.1016/j.intermet.2017.05.008
Maxime Dottor, Jean-Claude Crivello, Jean-Marc Joubert, Critical reassessment of the H–Nb system and experimental investigation and thermodynamic modeling of the H–Nb–Zr system, Calphad 83, 102617 (2023). doi:10.1016/j.calphad.2023.102617

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}
}