# AsGa: enthalpy of formation

> Enthalpy of formation of AsGa: 17 literature value(s) with sources, pages and quotes, from ORCHID.

HTML: https://data.orchid-project.org/compounds/AsGa.html · Markdown: https://data.orchid-project.org/compounds/AsGa.md

17 accepted literature formation-enthalpy value(s) (experimental 12, model 4, unspecified 1).

Systems: [As–Ga](https://data.orchid-project.org/systems/AS-GA.html)

## Literature values

Table: Enthalpy of formation of AsGa reported in the literature (17)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -53.12 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 21_ | Table II, p. 4, row 9; `ORC-V4ZIDESFZA` |  |
| -48.55 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Flow equilibration | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 23_ | Table II, p. 4, row 12; `ORC-FIW5M47YJY` |  |
| -47.1 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 20_ | Table II, p. 4, row 7; `ORC-K4ILT3GS7Y` |  |
| -46.22 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 19_ | Table II, p. 4, row 6; `ORC-KJWNJHO663` |  |
| -46.15 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 22_ | Table II, p. 4, row 10; `ORC-LPW3FDLTNP` |  |
| -46.02 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 18_ | Table II, p. 4, row 5; `ORC-2YODYIT2MI` |  |
| -46.02 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 21_ | Table II, p. 4, row 8; `ORC-7DES5PLTU4` |  |
| -45.22 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | Mass spectrometry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 22_ | Table II, p. 4, row 11; `ORC-JK6H5Z7III` |  |
| -43.85 kJ/mol (basis unstated) ± 2 | Ga0.5As0.5(c) | 298.15 | experimental | E.M.F. | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 16_ | Table II, p. 4, row 3; `ORC-DOJYKZWLEJ.877e10` |  |
| -39.75 kJ/mol (basis unstated) ± 1.7 | Ga0.5As0.5(c) | 298.15 | experimental | E.M.F. | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 17_ | Table II, p. 4, row 4; `ORC-JQ76SMQPC4.41fe71` |  |
| -39.68 kJ/mol (basis unstated) ± 0.6 | Ga0.5As0.5(c) | 298.15 | experimental | Solution calorimetry | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 14_ | Table II, p. 4, row 1; `ORC-F6B7KIYO2E` |  |
| -39.32 kJ/mol (basis unstated) ± 4 | Ga0.5As0.5(c) | 298.15 | experimental | E.M.F. | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [1] Ansara 1984; _cites ref. 15_ | Table II, p. 4, row 2; `ORC-7ROZH4CVVC.c6af34` |  |
| -105.3 kJ/mol (basis unstated) | GaAs | 298.15 | model |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [2] Onderka 2002; _cites Yamaguchi 1996_ | Table AI, p. 18, row 52; `ORC-OBO3SQIZDH` |  |
| -88.8 kJ/mol (basis unstated) | GaAs | 298.15 | model |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [2] Onderka 2002; _cites Ansara 1994_ | Table AI, p. 18, row 51; `ORC-YCZWXEBPI6.95146a` |  |
| -86.3 kJ/mol (basis unstated) | GaAs | 298.15 | model |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [2] Onderka 2002; _cites Kaufman 1981_ | Table AI, p. 18, row 50; `ORC-7XWIFRQNEB.b8a4c7` |  |
| -44.4256 kJ/mol (basis unstated) | Ga0.5As0.5(s) | 298.15 | model |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [3] Chatillon 1990 | Table 4, p. 11, row 4; `ORC-SIHQXKIML2.3e3181` |  |
| -71.1 kJ/mol (basis unstated) | GaAs | 298.15 | unspecified |  | [As–Ga](https://data.orchid-project.org/systems/AS-GA.html) | [2] Onderka 2002; _cites Wagman 1968_ | Table AI, p. 18, row 53; `ORC-VSQ5MV3EZG` |  |

### Uncertainty budget

Components kept separate, in the value's unit (literature [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md), [UNCERTAINTY_CALIBRATION.md](https://data.orchid-project.org/literature/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.

Table: Uncertainty budget of the literature values of AsGa

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -53.12 | kJ/mol (basis unstated) | 4 | 0.005 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -48.55 | kJ/mol (basis unstated) | 4 | 0.005 | 4.1 (experimental_unspecified, cleaned_below_threshold) |  |  |  | 4.1 |
| -47.1 | kJ/mol (basis unstated) | 4 | 0.05 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -46.22 | kJ/mol (basis unstated) | 4 | 0.005 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -46.15 | kJ/mol (basis unstated) | 4 | 0.005 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -46.02 | kJ/mol (basis unstated) | 4 | 0.005 | 3.5 (unknown, calibrated) |  |  |  | 4 |
| -46.02 | kJ/mol (basis unstated) | 4 | 0.005 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -45.22 | kJ/mol (basis unstated) | 4 | 0.005 | 4.2 (kems_vapour, calibrated) |  |  |  | 4.2 |
| -43.85 | kJ/mol (basis unstated) | 2 | 0.005 | 4.6 (emf, cleaned_below_threshold) |  |  |  | 4.6 |
| -39.75 | kJ/mol (basis unstated) | 1.7 | 0.005 | 4.6 (emf, cleaned_below_threshold) |  |  |  | 4.6 |
| -39.68 | kJ/mol (basis unstated) | 0.6 | 0.005 | 3.2 (solution_reaction_calorimetry, calibrated) |  |  |  | 3.2 |
| -39.32 | kJ/mol (basis unstated) | 4 | 0.005 | 4.6 (emf, cleaned_below_threshold) |  |  |  | 4.6 |
| -105.3 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -88.8 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -86.3 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -44.4256 | kJ/mol (basis unstated) |  | 5.000e-5 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -71.1 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |

## Sources

1. 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](https://doi.org/10.1016/0364-5916%2884%2990035-x)
2. 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](https://doi.org/10.1557/jmr.2002.0445)
3. C. Chatillon, I. Ansara, A. Watson, B.B. Argent, Re-assessment of the thermodynamic properties and phase diagrams of the Ga-As and In-As systems, Calphad 14, 203-214 (1990). [doi:10.1016/0364-5916(90)90021-q](https://doi.org/10.1016/0364-5916%2890%2990021-q)

## 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). https://doi.org/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). https://doi.org/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). https://doi.org/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.

```bibtex
@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}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\<id>, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).