Al–As system

16 accepted literature values from 2 paper(s) (experimental 8, model 6, unspecified 2); 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	8
model	6
unspecified	2

Accepted values by property group
Property group	Values
formation	11
heat capacity / entropy / enthalpy	5

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
AlAs-84Ans-LB.tdb	I. Ansara, D. Dutartre, Calphad, 8, 323-42(1984). doi:10.1016/0364-5916(84)90035-X	`17a1a9155346aacd533e1234a617e831efa3a6a7f832466fa62cc3791b84fac3`	viewer · TDB · JSON

Calculated three-phase invariants (model, mole fraction of the second component)
TDB file	T (K)	Phases at the invariant
AlAs-84Ans-LB.tdb	2052.43	LIQUID (x(As) 0.45908) + ZINCBLENDE_B3 (x(As) 0.5) + GAS (x(As) 0.99912)
AlAs-84Ans-LB.tdb	933.47	FCC_A1 (x(As) 0) + LIQUID (x(As) 0) + ZINCBLENDE_B3 (x(As) 0.5)
AlAs-84Ans-LB.tdb	933.33	FCC_A1 (x(As) 0) + LIQUID (x(As) 2.100e-4) + ZINCBLENDE_B3 (x(As) 0.5)
AlAs-84Ans-LB.tdb	933.33	FCC_A1 (x(As) 0) + LIQUID (x(As) 2.100e-4) + ZINCBLENDE_B3 (x(As) 0.5)
AlAs-84Ans-LB.tdb	888.4	ZINCBLENDE_B3 (x(As) 0.5) + RHOMBOHEDRAL_A7 (x(As) 1) + GAS (x(As) 1)

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, Al–As system (11)
Phase	Value	T (K)	Class	Source	Location
Al0.5As0.5(c)	-74.1 kJ/mol (basis unstated) ± 6.5	298.15	experimental	[1] Ansara 1984 cites ref. 40	Table V, p. 8, row 1 report
Al0.5As0.5(c)	-74.1 unknown ± 6.5	298.15	experimental	[1] Ansara 1984 cites ref. 40	Table V, p. 8, row 1 report
Al0.5As0.5(c)	-60.37 kJ/mol (basis unstated) ± 0.63	298.15	experimental	[1] Ansara 1984 cites ref. 14	Table V, p. 8, row 3 report
Al0.5As0.5(c)	-60.37 unknown ± 0.63	298.15	experimental	[1] Ansara 1984 cites ref. 14	Table V, p. 8, row 3 report
Al0.5As0.5(c)	-58.2 kJ/mol (basis unstated) ± 1.2	298.15	experimental	[1] Ansara 1984 cites ref. 38	Table V, p. 8, row 2 report
Al0.5As0.5(c)	-58.2 unknown ± 1.2	298.15	experimental	[1] Ansara 1984 cites ref. 38	Table V, p. 8, row 2 report
Al0.5As0.5(c)	-31 kJ/mol (basis unstated) ± 3.5	298.15	experimental	[1] Ansara 1984 cites ref. 41	Table V, p. 8, row 4 report
Al0.5As0.5(c)	-31 unknown ± 3.5	298.15	experimental	[1] Ansara 1984 cites ref. 41	Table V, p. 8, row 4 report
AlAs	-134.6 kJ/mol (basis unstated)	298.15	unspecified	[2] Onderka 2002 cites Wagman 1968	Table AI, p. 18, row 48 report
AlAs	-117.1 kJ/mol (basis unstated)	298.15	model	[2] Onderka 2002 cites Ansara 1994	Table AI, p. 18, row 47 report
AlAs	-117.1 kJ/mol (basis unstated)	298.15	model	[2] Onderka 2002 cites Kaufman 1981	Table AI, p. 18, row 49 report

Other properties

Heat capacity / entropy / enthalpy (5)

Heat capacity / entropy / enthalpy, Al–As system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S°298	56.21 J/mol-formula K	298.15	AlAs	model	[2] Onderka 2002 cites Ansara 1994	Table AI, p. 18, row 47 report
Entropy printed: ΔmS	70.9 J/mol-formula K	2039	AlAs	model	[2] Onderka 2002 cites Kaufman 1981	Table AI, p. 18, row 46 report
Entropy printed: °S^L - °S^f.c.c.	35.45 J/mol (basis unstated)/K	2043	Al0.5As0.5 alloy: As 0.5	unspecified	[1] Ansara 1984	Table VI, p. 13, row 5 report
Entropy printed: ΔmS	70.13 J/mol-formula K	2058	AlAs	model	[2] Onderka 2002 cites Ansara 1994	Table AI, p. 18, row 47 report
Heat capacity printed: Cp,298	24.48 J/mol (basis unstated)/K	298.15	AlAs	model	[2] Onderka 2002 cites Ansara 1994	Table AI, p. 18, row 47 report

Sources

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

I. Ansara, D. Dutartre, Thermodynamic study of the Al-Ga-As-Ge system, Calphad 8, 323-342 (1984). doi:10.1016/0364-5916(84)90035-x
B. Onderka, J. Unland, R. Schmid-Fetzer, Thermodynamics and phase stability in the In–N system, J. Mater. Res. 17, 3065-3083 (2002). doi:10.1557/jmr.2002.0445

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}
}