Hf–Os system

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

Data: JSON · CSV · interactive explorer · interactive phase diagram · phases (7) · papers (bibliography) · Markdown

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

Accepted values by property group
Property group	Values
invariant reaction	10
phase transition	4

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
HfOs-06Guo.tdb	C. Guo, Z. Du, J. Alloys Compd., 407, 188-92(2006). doi:10.1016/j.jallcom.2005.06.034	`a62b29616d7b427062c78afbe012638e4ddeabc91efea1d18c496415e9d6cee1`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
HfOs-06Guo.tdb	2823.29	B2_BCC (x(Os) 0.49951) + LIQUID (x(Os) 0.55754) + HFOS2_C14 (x(Os) 0.6516)
HfOs-06Guo.tdb	2797.94	HFOS2_C14 (x(Os) 0.67149) + LIQUID (x(Os) 0.77793) + HCP_A3 (x(Os) 0.94873)
HfOs-06Guo.tdb	1893.22	LIQUID (x(Os) 0.22572) + HF54OS17 (x(Os) 0.23944) + B2_BCC (x(Os) 0.45842)
HfOs-06Guo.tdb	1872.91	B2_BCC (x(Os) 0.13513) + LIQUID (x(Os) 0.20147) + HF54OS17 (x(Os) 0.23944)
HfOs-06Guo.tdb	1872.91	B2_BCC (x(Os) 0.1351) + LIQUID (x(Os) 0.20145) + HF54OS17 (x(Os) 0.23944)
HfOs-06Guo.tdb	1492.96	HCP_A3 (x(Os) 0.00415) + B2_BCC (x(Os) 0.09224) + HF54OS17 (x(Os) 0.23944)
HfOs-06Guo.tdb	1492.96	HCP_A3 (x(Os) 0.00415) + B2_BCC (x(Os) 0.09223) + HF54OS17 (x(Os) 0.23944)

Convex hulls: Materials Project DFT hull · OQMD DFT hull

Invariant reactions (literature)

Invariant reactions reported in the literature for the Hf–Os system (10)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
2823	eutectic: liq. -> HfOs + HfOs2	L: Os 0.536; HfOs: Os 0.51; HfOs2: Os 0.64	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 10 report
2823	eutectic: liq. -> HfOs + HfOs2	L: Os 0.5576; HfOs: Os 0.4995; HfOs2: Os 0.6518	model	[1] Guo 2006	Table 2, p. 4, row 9 report
2798	eutectic: liq. -> HfOs2 + hcp(Os)	L: Os 0.7779; HfOs2: Os 0.6715; hcp(Os): Os 0.9487	model	[1] Guo 2006	Table 2, p. 4, row 13 report
2798	eutectic: liq. -> HfOs2 + hcp(Os)	L: Os 0.793; HfOs2: Os 0.68; hcp(Os): Os 0.952	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 14 report
1893	liq. + HfOs -> Hf54Os17	L: Os 0.2257; HfOs: Os 0.4584; Hf54Os17: Os 0.239437	model	[1] Guo 2006	Table 2, p. 4, row 5 report
1893	liq. + HfOs -> Hf54Os17	L: Os 0.23; HfOs: Os 0.47; Hf54Os17: Os 0.239437	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 6 report
1873	eutectic: liq. -> bcc(Hf) + Hf54Os17	L: Os 0.2015; bcc(Hf): Os 0.1351; Hf54Os17: Os 0.239437	model	[1] Guo 2006	Table 2, p. 4, row 1 report
1873	eutectic: liq. -> bcc(Hf) + Hf54Os17	L: Os 0.201; bcc(Hf): Os 0.13; Hf54Os17: Os 0.239437	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 2 report
1493	bcc(Hf) -> hcp(Hf) + Hf54Os17	bcc(Hf): Os 0.098; hcp(Hf): Os 0.011; Hf54Os17: Os 0.239437	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 4 report
1493	bcc(Hf) -> hcp(Hf) + Hf54Os17	bcc(Hf): Os 0.0922; hcp(Hf): Os 0.0041; Hf54Os17: Os 0.239437	model	[1] Guo 2006	Table 2, p. 4, row 3 report

Other properties

Phase transition (4)

Phase transition, Hf–Os system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Phase transition	2868 K	2868	liq. -> HfOs L: Os 0.4918; HfOs: Os 0.4918	model	[1] Guo 2006	Table 2, p. 4, row 7 report
Phase transition	2868 K	2868	liq. -> HfOs L: Os 0.495; HfOs: Os 0.495	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 8 report
Phase transition	2953 K	2953	liq. -> HfOs2 L: Os 0.6623; HfOs2: Os 0.6623	model	[1] Guo 2006	Table 2, p. 4, row 11 report
Phase transition	2953 K	2953	liq. -> HfOs2 L: Os 0.667; HfOs2: Os 0.667	experimental	[1] Guo 2006 cites Eremenko 1993	Table 2, p. 4, row 12 report

Sources

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

Cuiping Guo, Zhenmin Du, Thermodynamic assessment of the Hf–Os system, Journal of Alloys and Compounds 407, 188-192 (2006). doi:10.1016/j.jallcom.2005.06.034

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}
}