Ga–O phases

11 phases (tier A 5, tier C 2, liquid 1, gas 2, needs_review 1); 5 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: interactive registry · full JSON · Ga–O system page · Markdown · field reference

Phases of the Ga–O system (11)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
ORTHORHOMBIC_A11 phase:ga-o:a11-orthorhombic	alpha-Ga · A11 · oC8 · Cmce (64)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–302.91 K, x(O) 0–0	0	1
BCC_A2 phase:ga-o:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
CORUNDUM_D51 phase:ga-o:d51-corundum	alpha-Al2O3 · D5_1 · hR10 · R-3c (167)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	not stable in 1 calculated diagram(s)	0	1
FCC_A1 phase:ga-o:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
GA2O3_BETA phase:ga-o:ga2o3-beta	beta-Ga2O3 · mC20 · C2/m (12)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–867.91 K, x(O) 0.6–0.6	4	1
GA2O3_D53 phase:ga-o:ga2o3-d53	Mn2O3 · D5_3 · cI80 · Ia-3 (206)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1	1
GA2O3_H11 phase:ga-o:ga2o3-h11		needs_review	not stable in 1 calculated diagram(s)	1	1
GAS phase:ga-o:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 1603.22–2500 K, x(O) 0.00188–0.33796	1	1
HCP_A3 phase:ga-o:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
ION phase:ga-o:ion	liquid	liquid	stable in 1 of 1 calculated diagram(s): 302.91–2500 K, x(O) 0–0.5996	0	1
O2GAS phase:ga-o:o2gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300–445 K, x(O) 1–1	0	1

ORTHORHOMBIC_A11 (Ga–O)

Id: phase:ga-o:a11-orthorhombic; status assigned
Structure: alpha-Ga · A11 · oC8 · Cmce (64); type st:a11-alpha-ga-oc8; tier A: standard phase name; confidence high
Stoichiometry: Ga 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–302.91 K, x(O) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:a11-orthorhombic
tdb: tdb:GaO-04Zin.tdb:ORTHORHOMBIC_A11

TDB models of ORTHORHOMBIC_A11 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: ORTHORHOMBIC_A11, type code %, sha256 3fb8f43e1c88636a…

56: PHASE ORTHORHOMBIC_A11 % 1 1 !
57: CONST ORTHORHOMBIC_A11 : GA : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

BCC_A2 (Ga–O)

Id: phase:ga-o:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stoichiometry: Ga 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:bcc-a2
tdb: tdb:GaO-04Zin.tdb:BCC_A2

TDB models of BCC_A2 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: BCC_A2, type code %B, sha256 3fb8f43e1c88636a…

46: PHASE BCC_A2 %B 2 1 3 !
47: CONST BCC_A2 : GA : VA : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

CORUNDUM_D51 (Ga–O)

Id: phase:ga-o:d51-corundum; status assigned
Structure: alpha-Al2O3 · D5_1 · hR10 · R-3c (167); type st:d5-1-alpha-al2o3-hr10; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
Caveat: not certain from the name or DFT alone (unrecognised_name_tokens:CORUNDUM); structure as stated in the SGTE crystallographic table for this phase name and system
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:d51-corundum
tdb: tdb:GaO-04Zin.tdb:CORUNDUM_D51

TDB models of CORUNDUM_D51 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: CORUNDUM_D51, type code %, sha256 3fb8f43e1c88636a…

61: PHASE CORUNDUM_D51:I % 2 2 3 !
62: CONST CORUNDUM_D51:I : GA+3 : O-2 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

FCC_A1 (Ga–O)

Id: phase:ga-o:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Ga 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:fcc-a1
tdb: tdb:GaO-04Zin.tdb:FCC_A1

TDB models of FCC_A1 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: FCC_A1, type code %A, sha256 3fb8f43e1c88636a…

41: PHASE FCC_A1 %A 2 1 1 !
42: CONST FCC_A1 : GA : VA : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

GA2O3_BETA (Ga–O)

Id: phase:ga-o:ga2o3-beta; status assigned
Structure: beta-Ga2O3 · mC20 · C2/m (12); type st:beta-ga2o3-mc20; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
Caveat: not certain from the name or DFT alone (no_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
Stability: stable in 1 of 1 calculated diagram(s): 300–867.91 K, x(O) 0.6–0.6
Literature: 4 values (4 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ga-o:ga2o3-beta
paper: paper:10.1111/j.1551-2916.2004.00683.x:β-Ga2O3
tdb: tdb:GaO-04Zin.tdb:GA2O3_BETA

TDB models of GA2O3_BETA (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: GA2O3_BETA, type code %, sha256 3fb8f43e1c88636a…

66: PHASE GA2O3_BETA:I % 2 2 3 !
67: CONST GA2O3_BETA:I : GA+3 : O-2 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase; reports values for this phase

GA2O3_D53 (Ga–O)

Id: phase:ga-o:ga2o3-d53; status assigned
Structure: Mn2O3 · D5_3 · cI80 · Ia-3 (206); type st:d5-3-mn2o3-ci80; tier A: standard phase name; confidence high
Stability: not stable in 1 calculated diagram(s)
Literature: 1 values (1 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ga-o:ga2o3-d53
paper: paper:10.1111/j.1551-2916.2004.00683.x:δ-Ga2O3†
tdb: tdb:GaO-04Zin.tdb:GA2O3_D53

TDB models of GA2O3_D53 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: GA2O3_D53, type code %, sha256 3fb8f43e1c88636a…

76: PHASE GA2O3_D53:I % 2 2 3 !
77: CONST GA2O3_D53:I : GA+3 : O-2 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase; reports values for this phase

GA2O3_H11 (Ga–O)

Id: phase:ga-o:ga2o3-h11; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:site_ratios_contradict_H1_1; site_ratios_contradict_H1_1:GaO-04Zin.tdb
Candidate (name_token): Al2MgO4 · H1_1 · cF56 · Fd-3m (227) — Strukturbericht/word 'H11' in the TDB name
Candidate (sgte_mmc2): Al2MgO4 · H1_1 · cF56 · Fd-3m (227) — Hallstedt 2025 mmc2 row for GA2O3_H11: gamma-Ga2O3 (metastable)
Candidate (tdb_comment): Al2MgO4 · cF56 · Fd-3m — GaO-04Zin.tdb: 'Prototype Al2MgO4 (cF56, Fd-3m), gamma-Ga2O3'
Stability: not stable in 1 calculated diagram(s)
Literature: 1 values (1 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ga-o:ga2o3-h11
paper: paper:10.1111/j.1551-2916.2004.00683.x:γ-Ga2O3†
tdb: tdb:GaO-04Zin.tdb:GA2O3_H11

TDB models of GA2O3_H11 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: GA2O3_H11, type code %, sha256 3fb8f43e1c88636a…

71: PHASE GA2O3_H11:I % 2 2 3 !
72: CONST GA2O3_H11:I : GA+3 : O-2 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase; reports values for this phase

GAS (Ga–O)

Id: phase:ga-o:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1603.22–2500 K, x(O) 0.00188–0.33796
Literature: 1 values (1 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ga-o:gas
paper: paper:10.1111/j.1551-2916.2004.00683.x:gas
tdb: tdb:GaO-04Zin.tdb:GAS

TDB models of GAS (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: GAS, type code %, sha256 3fb8f43e1c88636a…

79: PHASE GAS:G % 1 1 !
80: CONST GAS:G : GA GA2 GAO GA2O O O2% O3 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase; reports values for this phase

HCP_A3 (Ga–O)

Id: phase:ga-o:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stoichiometry: Ga 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:hcp-a3
tdb: tdb:GaO-04Zin.tdb:HCP_A3

TDB models of HCP_A3 (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: HCP_A3, type code %A, sha256 3fb8f43e1c88636a…

51: PHASE HCP_A3 %A 2 1 0.5 !
52: CONST HCP_A3 : GA : VA : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

ION (Ga–O)

Id: phase:ga-o:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 302.91–2500 K, x(O) 0–0.5996
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:ion
tdb: tdb:GaO-04Zin.tdb:ION

TDB models of ION (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: ION, type code %, sha256 3fb8f43e1c88636a…

36: PHASE ION:Y % 2 1 1 !
37: CONST ION:Y : GA+3 : O-2 VA O : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

O2GAS (Ga–O)

Id: phase:ga-o:o2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–445 K, x(O) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ga-o:o2gas
tdb: tdb:GaO-04Zin.tdb:O2GAS

TDB models of O2GAS (1): PHASE and CONSTITUENT statements as written

GaO-04Zin.tdb: O2GAS, type code %, sha256 3fb8f43e1c88636a…

82: PHASE O2GAS % 1 1 !
83: CONST O2GAS : O2 : !

Example references (1 of 1; assessments first):

doi:10.1111/j.1551-2916.2004.00683.x Matvei Zinkevich, Fritz Aldinger, Thermodynamic Assessment of the Gallium‐Oxygen System, Journal of the American Ceramic Society 87, 683-691 (2004).
assessment that models this phase

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735970
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 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); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). 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_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  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}
}