O–Sr phases

8 phases (tier A 4, liquid 1, gas 2, needs_review 1); 7 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 · O–Sr system page · Markdown · field reference

Phases of the O–Sr system (8)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
BCC_A2 phase:o-sr:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1047–2500 K, x(O) 0–0	0	1
FCC_A1 phase:o-sr:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–817.5 K, x(O) 0–0	0	1
GAS phase:o-sr:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 1644.54–2500 K, x(O) 0–0.99996	0	1
HCP_A3 phase:o-sr: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:o-sr:ion	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1047–2500 K, x(O) 0–0.07	0	1
O2GAS phase:o-sr:o2gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300–325 K, x(O) 1–1	0	1
SRO_B1 phase:o-sr:sro-b1	NaCl · B1 · cF8 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2500 K, x(O) 0.5–0.5	7	1
SRO2_C11A phase:o-sr:sro2-c11a		needs_review	stable in 1 of 1 calculated diagram(s): 300–495 K, x(O) 0.66667–0.66667	0	1

BCC_A2 (O–Sr)

Id: phase:o-sr:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stoichiometry: Sr 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 1047–2500 K, x(O) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:bcc-a2
tdb: tdb:SrO-96Ris-LB.tdb:BCC_A2

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

SrO-96Ris-LB.tdb: BCC_A2, type code %B, sha256 a0cbfdaeb5428ddd…

47: PHASE BCC_A2 %B 2 1 3 !
48: CONST BCC_A2 : SR : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

FCC_A1 (O–Sr)

Id: phase:o-sr:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–817.5 K, x(O) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:fcc-a1
tdb: tdb:SrO-96Ris-LB.tdb:FCC_A1

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

SrO-96Ris-LB.tdb: FCC_A1, type code %A, sha256 a0cbfdaeb5428ddd…

42: PHASE FCC_A1 %A 2 1 1 !
43: CONST FCC_A1 : SR : VA% O : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

GAS (O–Sr)

Id: phase:o-sr:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1644.54–2500 K, x(O) 0–0.99996
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:gas
tdb: tdb:SrO-96Ris-LB.tdb:GAS

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

SrO-96Ris-LB.tdb: GAS, type code %, sha256 a0cbfdaeb5428ddd…

68: PHASE GAS:G % 1 1 !
69: CONST GAS:G : O O2 O3 SR SR2 SRO : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

HCP_A3 (O–Sr)

Id: phase:o-sr: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: Sr 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:o-sr:hcp-a3
tdb: tdb:SrO-96Ris-LB.tdb:HCP_A3

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

SrO-96Ris-LB.tdb: HCP_A3, type code %A, sha256 a0cbfdaeb5428ddd…

52: PHASE HCP_A3 %A 2 1 0.5 !
53: CONST HCP_A3 : SR : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

ION (O–Sr)

Id: phase:o-sr:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1047–2500 K, x(O) 0–0.07
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:ion
tdb: tdb:SrO-96Ris-LB.tdb:ION

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

SrO-96Ris-LB.tdb: ION, type code %, sha256 a0cbfdaeb5428ddd…

37: PHASE ION:Y % 2 1 1 !
38: CONST ION:Y : SR+2 : O-2 VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

O2GAS (O–Sr)

Id: phase:o-sr:o2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–325 K, x(O) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:o2gas
tdb: tdb:SrO-96Ris-LB.tdb:O2GAS

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

SrO-96Ris-LB.tdb: O2GAS, type code %, sha256 a0cbfdaeb5428ddd…

65: PHASE O2GAS % 1 1 !
66: CONST O2GAS : O2 :!

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase

SRO_B1 (O–Sr)

Id: phase:o-sr:sro-b1; status assigned
Structure: NaCl · B1 · cF8 · Fm-3m (225); type st:b1-nacl-cf8; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2500 K, x(O) 0.5–0.5
Literature: 7 values (7 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:o-sr:sro-b1
paper: paper:10.1016/s0364-5916(96)00037-5:SrO
tdb: tdb:SrO-96Ris-LB.tdb:SRO_B1

TDB models of SRO_B1 (1): PHASE and CONSTITUENT statements as written

SrO-96Ris-LB.tdb: SRO_B1, type code %, sha256 a0cbfdaeb5428ddd…

57: PHASE SRO_B1:I % 2 1 1 !
58: CONST SRO_B1:I : SR+2 : O-2 : !

Example references (2 of 2; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
assessment that models this phase; reports values for this phase
doi:10.1016/0038-092x(65)90162-3 Marc Foex, Measurement of the solidification points of several refractory oxides by means of a solar furnace, Solar Energy 9, 61-67 (1965).
cited as the source of values for this phase

SRO2_C11A (O–Sr)

Id: phase:o-sr:sro2-c11a; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:site_ratios_contradict_C11_a; site_ratios_contradict_C11_a:SrO-96Ris-LB.tdb
Candidate (name_token): CaC2 · C11_a · tI6 · I4/mmm (139) — Strukturbericht/word 'C11A' in the TDB name
Candidate (sgte_mmc2): CaC2 · C11_a · tI6 · I4/mmm (139) — Hallstedt 2025 mmc2 row for SRO2_C11A: SrO2 (peroxide)
Candidate (tdb_comment): CaC2 · tI6 · I4/mmm — SrO-96Ris-LB.tdb: 'Prototype CaC2 (tI6, I4/mmm); Strontium peroxide'
Stability: stable in 1 of 1 calculated diagram(s): 300–495 K, x(O) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:o-sr:sro2-c11a
tdb: tdb:SrO-96Ris-LB.tdb:SRO2_C11A

TDB models of SRO2_C11A (1): PHASE and CONSTITUENT statements as written

SrO-96Ris-LB.tdb: SRO2_C11A, type code %, sha256 a0cbfdaeb5428ddd…

62: PHASE SRO2_C11A:I % 2 1 1 !
63: CONST SRO2_C11A:I : SR+2 : O2-2 : !

Example references (1 of 1; assessments first):

doi:10.1016/S0364-5916(96)00037-5 D. Risold, B. Hallstedt, L.J. Gauckler, Calphad, 20, 353-61(1996).
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}
}