# O–Sr system > O–Sr system: 24 accepted literature values (formation 11, phase transition 7, heat capacity / entropy / enthalpy 6) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/O-SR.html · Markdown: https://data.orchid-project.org/systems/O-SR.md 24 accepted literature values from 1 paper(s) (experimental 13, model 2, unspecified 9); 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/O-SR.json) · [CSV](https://data.orchid-project.org/systems/O-SR.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#O-SR) · [phases (8)](https://data.orchid-project.org/phases/pages/O-SR.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/O-SR.html) · [Markdown](https://data.orchid-project.org/systems/O-SR.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 13 | | model | 2 | | unspecified | 9 | Table: Accepted values by property group | Property group | Values | |---|---:| | phase transition | 7 | | formation | 11 | | heat capacity / entropy / enthalpy | 6 | Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/O/O-SR.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/O/O-SR.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, O–Sr system (11) | Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote | |---|---|---:|---:|---|---:|---:|---|---|---| | SrO | | -643 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites ref. 93Ono_ | Table 3, p. 4, row 3; `ORC-VSDUSBJZQX` | | | SrO | | -604.3 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites Mah 1963_ | Table 3, p. 4, row 2; `ORC-DJGRCWP2VD` | | | SrO | | -595 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites ref. 93Ono_ | Table 3, p. 4, row 4; `ORC-BDJN7MCYVE` | | | SrO | | -592.15 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Risold 1996 | Table 3, p. 4, row 7; `ORC-53GBR4CZAV` | | | SrO | | -592.15 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites ref. 90Cor_ | Table 3, p. 4, row 1; `ORC-LZQRI7PQAG` | | | SrO | | -592.04 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Risold 1996; _cites Chase 1985_ | Table 3, p. 4, row 5; `ORC-KPLXIURRCH` | | | SrO | | -591.01 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Risold 1996; _cites ref. 94_ | Table 3, p. 4, row 6; `ORC-UFAUFXD4T5` | | | SrO2 | | -636 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Risold 1996 | Table 4, p. 4, row 4; `ORC-C7M6RPVFGD` | | | SrO2 | | -635 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites M_ | Table 4, p. 4, row 1; `ORC-P6SW3WEVOB` | | | SrO2 | | -633 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Risold 1996; _cites ref. 94_ | Table 4, p. 4, row 3; `ORC-MKRSVUMGWL` | | | SrO2 | | -631 kJ/mol (basis unstated) | 298.15 | experimental | | | [1] Risold 1996; _cites Vedeneev_ | Table 4, p. 4, row 2; `ORC-3TI3ZFL7LI` | | ## Other properties ### Phase transition (7) Table: Phase transition, O–Sr system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Phase transition | 2703 K | 2703 | congruent melting: \[26Sch\]; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites ref. 26Sch_ | Table 1, p. 4, row 1; `ORC-5G2VQ2DKPW` | | | Phase transition | 2805 K | 2805 | congruent melting: \[85Irg\]; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Properties 1985_ | Table 1, p. 4, row 2; `ORC-H4VPNPPXZV` | | | Phase transition | 2805 K | 2805 | congruent melting: \[94SGT\]; _alloy: Sr 0.5_ | model | [1] Risold 1996; _cites ref. 94_ | Table 1, p. 4, row 6; `ORC-VTORQEQ7FX` | | | Phase transition | 2870 K | 2870 | congruent melting: This work; _alloy: Sr 0.5_ | unspecified | [1] Risold 1996 | Table 1, p. 4, row 7; `ORC-2GLEK3S24V` | | | Phase transition | 2872 K | 2872 | congruent melting: \[69Nog\]; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Noguchi 1969_ | Table 1, p. 4, row 3; `ORC-V2PUOMAGGR` | | | Phase transition | 2938 K | 2938 | congruent melting: \[65Foe\]; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Foex 1965_ [doi](https://doi.org/10.1016/0038-092x%2865%2990162-3) | Table 1, p. 4, row 4; `ORC-27DX77GOCD` | | | Phase transition | 2938 K | 2938 | congruent melting: \[85Cha\]; _alloy: Sr 0.5_ | model | [1] Risold 1996; _cites Chase 1985_ | Table 1, p. 4, row 5; `ORC-QJ2Z6J2JJ4` | | ### Heat capacity / entropy / enthalpy (6) Table: Heat capacity / entropy / enthalpy, O–Sr system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Entropy; _printed: S^298_ | 55.56 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | unspecified | [1] Risold 1996; _cites ref. 94_ | Table 2, p. 4, row 5; `ORC-3PA7P2PCHY` | | | Entropy; _printed: S^298_ | 53.63 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Cordfunke_ [doi](https://doi.org/10.1016/0021-9614%2890%2990188-v) | Table 2, p. 4, row 3; `ORC-7AIBLLA4ZF` | | | Entropy; _printed: S^298_ | 54.4 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Anderson 1935_ [doi](https://doi.org/10.1021/ja01306a012) | Table 2, p. 4, row 1; `ORC-JVB3SV62QQ` | | | Entropy; _printed: S^298_ | 53.58 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | unspecified | [1] Risold 1996 | Table 2, p. 4, row 6; `ORC-OI7HQ2WKOQ` | | | Entropy; _printed: S^298_ | 55.52 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | unspecified | [1] Risold 1996; _cites Chase 1985_ | Table 2, p. 4, row 4; `ORC-R4OTIX3PR5` | | | Entropy; _printed: S^298_ | 55.52 J/mol (basis unstated)/K | 298.15 | SrO; _alloy: Sr 0.5_ | experimental | [1] Risold 1996; _cites Gmelin 1969_ [doi](https://doi.org/10.1515/zna-1969-1120) | Table 2, p. 4, row 2; `ORC-V4IXN2I672` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. Daniel Risold, Bengt Hallstedt, Ludwig J. Gauckler, The strontium-oxygen system, Calphad 20, 353-361 (1996). [doi:10.1016/s0364-5916(96)00037-5](https://doi.org/10.1016/s0364-5916%2896%2900037-5) ## 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=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).