# As–Ga system

> As–Ga system: 70 accepted literature values (phase transition 44, formation 17, heat capacity / entropy / enthalpy 9) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/AS-GA.html · Markdown: https://data.orchid-project.org/systems/AS-GA.md

70 accepted literature values from 4 paper(s) (experimental 59, model 9, unspecified 2); 0 calculated phase diagram(s). 1 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: [JSON](https://data.orchid-project.org/literature/systems/AS-GA.json) · [CSV](https://data.orchid-project.org/systems/AS-GA.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#AS-GA) · [phases (8)](https://data.orchid-project.org/phases/pages/AS-GA.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/AS-GA.html) · [Markdown](https://data.orchid-project.org/systems/AS-GA.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 59 |
| model | 9 |
| unspecified | 2 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| phase transition | 44 |
| formation | 17 |
| heat capacity / entropy / enthalpy | 9 |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/AS/AS-GA.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/AS/AS-GA.json)

## 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](https://data.orchid-project.org/literature/dft_parity.json).

Table: Enthalpies of formation, As–Ga system (17)

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

## Other properties

### Phase transition (44)

Table: Phase transition, As–Ga system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 960 K | 960 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 9; `ORC-PSIOMBPWPF` |  |
| Phase transition | 964 K | 964 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 24; `ORC-EX4CX5UU3B` |  |
| Phase transition | 965 K | 965 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 23; `ORC-PHBOGA33AA` |  |
| Phase transition | 965 K | 965 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 10; `ORC-LW2PVSL3TD` |  |
| Phase transition | 981 K | 981 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 26; `ORC-4AGYAF52XV` |  |
| Phase transition | 981 K | 981 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 25; `ORC-JXXPNJRQ23` |  |
| Phase transition | 1000 K | 1000 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 11; `ORC-K5QJY232TY` |  |
| Phase transition | 1003 K | 1003 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 12; `ORC-AUVHBQUDQU` |  |
| Phase transition | 1009 K | 1009 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 28; `ORC-2KH7KUMEUA` |  |
| Phase transition | 1009 K | 1009 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 27; `ORC-AVKJHT2WT2` |  |
| Phase transition | 1023 K | 1023 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 30; `ORC-X6UFUR2VOQ` |  |
| Phase transition | 1024 K | 1024 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 29; `ORC-6FAFMKY5BU` |  |
| Phase transition | 1026 K | 1026 | other: Ankri (6) | experimental | [1] Ansara 1984; _cites ref. 6_ | Table I, p. 3, row 1; `ORC-W4LXJICCAF` |  |
| Phase transition | 1028 K | 1028 | other: Ankri (6) | experimental | [1] Ansara 1984 | Table I, p. 3, row 2; `ORC-JSR3W6ZVF3` |  |
| Phase transition | 1034 K | 1034 | other: Ankri (6) | experimental | [1] Ansara 1984; _cites ref. 6_ | Table I, p. 3, row 3; `ORC-WYQLVW2EMD` |  |
| Phase transition | 1037 K | 1037 | other: Ankri (6) | experimental | [1] Ansara 1984 | Table I, p. 3, row 4; `ORC-SQPT45YQSC` |  |
| Phase transition | 1049 K | 1049 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 32; `ORC-AZZ3ZR4IGH` |  |
| Phase transition | 1050 K | 1050 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 13; `ORC-PEEPSUHXUL` |  |
| Phase transition | 1051 K | 1051 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 31; `ORC-GNCT56LEKJ` |  |
| Phase transition | 1052 K | 1052 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 14; `ORC-6R6V7WYWGE` |  |
| Phase transition | 1071 K | 1071 | other: Ankri (6) | experimental | [1] Ansara 1984; _cites ref. 6_ | Table I, p. 3, row 5; `ORC-KNZ2MD3F5D` |  |
| Phase transition | 1073 K | 1073 | other: Ankri (6) | experimental | [1] Ansara 1984; _cites ref. 6_ | Table I, p. 3, row 7; `ORC-FYZ6RNOJEV` |  |
| Phase transition | 1073 K | 1073 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 34; `ORC-O6IW5Q4HWF` |  |
| Phase transition | 1073 K | 1073 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 15; `ORC-RFVUNZBFID` |  |
| Phase transition | 1074 K | 1074 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 36; `ORC-K427Y7M3EO` |  |
| Phase transition | 1074 K | 1074 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 16; `ORC-AEZFU76RN7` |  |
| Phase transition | 1075 K | 1075 | other: Ankri (6) | experimental | [1] Ansara 1984 | Table I, p. 3, row 6; `ORC-I2FGUVAV7P` |  |
| Phase transition | 1075 K | 1075 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 33; `ORC-7WQOOBVHXT` |  |
| Phase transition | 1076 K | 1076 | other: Ankri (6) | experimental | [1] Ansara 1984 | Table I, p. 3, row 8; `ORC-4PQGIEEWRY` |  |
| Phase transition | 1077 K | 1077 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 35; `ORC-HK53HOTWOP` |  |
| Phase transition | 1100 K | 1100 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 17; `ORC-GJPMDILVV4` |  |
| Phase transition | 1101 K | 1101 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 38; `ORC-3YEYOB56CM` |  |
| Phase transition | 1101 K | 1101 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 37; `ORC-C6VOB3BYEG` |  |
| Phase transition | 1101 K | 1101 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 18; `ORC-XCESPY5NPS` |  |
| Phase transition | 1125 K | 1125 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 40; `ORC-DFLPJFQKMH` |  |
| Phase transition | 1126 K | 1126 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 39; `ORC-XH6VCMBTMV` |  |
| Phase transition | 1150 K | 1150 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 19; `ORC-COGMNDCUDY` |  |
| Phase transition | 1152 K | 1152 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 20; `ORC-4H4U2MHX7J` |  |
| Phase transition | 1172 K | 1172 | other: Dutartre (8) | experimental | [1] Ansara 1984 | Table I, p. 3, row 42; `ORC-JFCUIJDVES` |  |
| Phase transition | 1173 K | 1173 | other: Dutartre (8) | experimental | [1] Ansara 1984; _cites ref. 8_ | Table I, p. 3, row 41; `ORC-C6DJFPFXYU` |  |
| Phase transition | 1190 K | 1190 | other: Hsieh (7) | experimental | [1] Ansara 1984; _cites ref. 7_ | Table I, p. 3, row 21; `ORC-JYDMDY7P7F` |  |
| Phase transition | 1196 K | 1196 | other: Hsieh (7) | experimental | [1] Ansara 1984 | Table I, p. 3, row 22; `ORC-QEWG4ESHMR` |  |
| Phase transition | 1510 K | 1510 | congruent transformation | experimental | [4] Ghasemi 2015 | p. 1; `ORC-377Y6SVMD4` | “In the As-Ga system, there are three solution phases, liquid, (Ga) and (As) and one stoichiometric phase, GaAs, with zinc-blende structure which melts congruently at 1510 K.” |
| Phase transition | 1511 K | 1511 | GaAs | experimental | [1] Ansara 1984 | p. 1; `ORC-DV64AU2P4V` | “Klister and Thoma ( ) using a differential temperature analysis, measured a melting temperature qf 1511 K.” |

### Heat capacity / entropy / enthalpy (9)

Table: Heat capacity / entropy / enthalpy, As–Ga system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: ΔS°298_ | 9.62 kJ/mol°K ± 5 | 298.15 | Ga0.5As0.5(c) | experimental | [1] Ansara 1984; _cites ref. 15_ | Table II, p. 4, row 2; `ORC-7ROZH4CVVC.8185d8` |  |
| Entropy; _printed: ΔS°298_ | -19.5 kJ/mol°K ± 4 | 298.15 | Ga0.5As0.5(c) | experimental | [1] Ansara 1984; _cites ref. 16_ | Table II, p. 4, row 3; `ORC-DOJYKZWLEJ.6dc132` |  |
| Entropy; _printed: ΔS°298_ | -14.31 kJ/mol°K ± 1.7 | 298.15 | Ga0.5As0.5(c) | experimental | [1] Ansara 1984; _cites ref. 17_ | Table II, p. 4, row 4; `ORC-JQ76SMQPC4.a56fb6` |  |
| Entropy; _printed: S°(298.15K)_ | 31.442 J/mol (basis unstated)/K | 298.15 | Ga0.5As0.5(s); _alloy: Ga 0.5_ | model | [2] Chatillon 1990 | Table 4, p. 11, row 4; `ORC-SIHQXKIML2.b7130d` |  |
| Entropy; _printed: S°298_ | 62.91 J/mol-formula K | 298.15 | GaAs | model | [3] Onderka 2002; _cites Ansara 1994_ | Table AI, p. 18, row 51; `ORC-YCZWXEBPI6.8e7351` |  |
| Entropy; _printed: ΔmS_ | 70.41 J/mol-formula K | 1510 | GaAs | model | [3] Onderka 2002; _cites Ansara 1994_ | Table AI, p. 18, row 51; `ORC-YCZWXEBPI6.df01fe` |  |
| Entropy; _printed: ΔmS_ | 70.11 J/mol-formula K | 1512 | GaAs | model | [3] Onderka 2002; _cites Kaufman 1981_ | Table AI, p. 18, row 50; `ORC-7XWIFRQNEB.387f80` |  |
| Entropy; _printed: °S^L - °S^f.c.c._ | 34.68 J/mol (basis unstated)/K | 1513 | Ga0.5As0.5; _alloy: As 0.5, Ga 0.5_ | unspecified | [1] Ansara 1984 | Table VI, p. 13, row 4; `ORC-TXRDRG5FEA.fc9fa2` |  |
| Heat capacity; _printed: Cp,298_ | 46.85 J/mol (basis unstated)/K | 298.15 | GaAs | model | [3] Onderka 2002; _cites Ansara 1994_ | Table AI, p. 18, row 51; `ORC-YCZWXEBPI6.e6c39a` |  |

## Sources

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

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. 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)
3. 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)
4. Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015). [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051)

## 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-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). https://doi.org/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). 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); 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_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}
}
```

---

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/).