# Ce–O system

> Ce–O system: 90 accepted literature values (invariant reaction 48, crystal structure 22, phase equilibrium 12, phase transition 6) and 2 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/CE-O.html · Markdown: https://data.orchid-project.org/systems/CE-O.md

90 accepted literature values from 3 paper(s) (experimental 51, model 29, unspecified 10); 2 calculated phase diagram(s). 5 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/CE-O.json) · [CSV](https://data.orchid-project.org/systems/CE-O.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#CE-O) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#CE-O/CeO-06Zin.json) · [phases (19)](https://data.orchid-project.org/phases/pages/CE-O.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/CE-O.html) · [Markdown](https://data.orchid-project.org/systems/CE-O.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 51 |
| model | 29 |
| unspecified | 10 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 48 |
| phase transition | 6 |
| phase equilibrium | 12 |
| formation | 1 |
| heat capacity / entropy / enthalpy | 1 |
| crystal structure | 22 |

## Calculated phase diagrams

Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model.

Table: Assessments with a calculated phase diagram

| TDB file | Assessment | SHA-256 | Links |
|---|---|---|---|
| CeO-06Zin.tdb | M. Zinkevich, D. Djurovic, F. Aldinger, Solid State Ionics, 177, 989-1001(2006). [doi:10.1016/j.ssi.2006.02.044](https://doi.org/10.1016/j.ssi.2006.02.044) | `3e9afdf3d632ed92a545cdbb44b9053159e64a22da8fab0f8874e7119e0742f4` | [viewer](https://orchid-project.org/phase-diagrams/#CE-O/CeO-06Zin.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CeO-06Zin.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CeO-06Zin.json) |
| CeO-08Dju.tdb | D. Djurovic, M. Zinkevich, F. Aldinger, Solid State Ionics, 179, 1902-11(2008). [doi:10.1016/j.ssi.2008.06.011](https://doi.org/10.1016/j.ssi.2008.06.011) | `f4f16a6dae7120a8e76e4d1338142a8b5828227ff3a7a7f06df9f0cdd3997600` | [viewer](https://orchid-project.org/phase-diagrams/#CE-O/CeO-08Dju.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CeO-08Dju.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CeO-08Dju.json) |

Table: Calculated three-phase invariants (model, mole fraction of the second component)

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| CeO-06Zin.tdb | 2471.49 | LIQUID (x(O) 0.63936) + CE62O112 (x(O) 0.64368) + GAS (x(O) 1) |
| CeO-06Zin.tdb | 2469.6 | LIQUID (x(O) 0.63912) + CE40O72 (x(O) 0.64286) + CE62O112 (x(O) 0.64368) |
| CeO-06Zin.tdb | 2416.78 | LIQUID (x(O) 0.51016) + ION (x(O) 0.52277) + X_R2O3 (x(O) 0.57274) |
| CeO-06Zin.tdb | 2416.14 | CE62O112 (x(O) 0.64368) + CE11O20 (x(O) 0.64516) + GAS (x(O) 1) |
| CeO-06Zin.tdb | 2413 | LIQUID (x(O) 0.50656) + X_R2O3 (x(O) 0.57255) + H_R2O3 (x(O) 0.57255) |
| CeO-06Zin.tdb | 2413 | H_R2O3 (x(O) 0.59253) + X_R2O3 (x(O) 0.59253) + ION (x(O) 0.60059) |
| CeO-06Zin.tdb | 2361.24 | LIQUID (x(O) 0.63143) + CE19O34 (x(O) 0.64151) + CE40O72 (x(O) 0.64286) |
| CeO-06Zin.tdb | 2293.5 | LIQUID (x(O) 0.62835) + CE9O16 (x(O) 0.64) + CE19O34 (x(O) 0.64151) |
| CeO-06Zin.tdb | 2027.12 | LIQUID (x(O) 0.15131) + H_R2O3#2 (x(O) 0.54663) + H_R2O3 (x(O) 0.56414) |
| CeO-06Zin.tdb | 1760.54 | ION (x(O) 0.04374) + LIQUID (x(O) 0.06211) + H_R2O3 (x(O) 0.51823) |
| CeO-06Zin.tdb | 1080.24 | ION (x(O) 0.00117) + BCC_A2 (x(O) 0.00578) + H_R2O3 (x(O) 0.5016) |
| CeO-06Zin.tdb | 1005 | BCC_A2 (x(O) 0.00314) + FCC_A1 (x(O) 0.0049) + H_R2O3 (x(O) 0.50107) |
| CeO-06Zin.tdb | 435.98 | CE19O34 (x(O) 0.64151) + CE40O72 (x(O) 0.64286) + CE62O112 (x(O) 0.64368) |
| CeO-06Zin.tdb | 431.2 | CE19O34 (x(O) 0.64151) + CE62O112 (x(O) 0.64368) + CE11O20 (x(O) 0.64516) |
| CeO-06Zin.tdb | 420.08 | CE9O16 (x(O) 0.64) + CE19O34 (x(O) 0.64151) + CE11O20 (x(O) 0.64516) |
| CeO-06Zin.tdb | 398.92 | CE7O12 (x(O) 0.63158) + CE9O16 (x(O) 0.64) + CE11O20 (x(O) 0.64516) |
| CeO-08Dju.tdb | 2471.49 | LIQUID (x(O) 0.63936) + CE62O112 (x(O) 0.64368) + GAS (x(O) 1) |
| CeO-08Dju.tdb | 2469.6 | LIQUID (x(O) 0.63912) + CE40O72 (x(O) 0.64286) + CE62O112 (x(O) 0.64368) |
| CeO-08Dju.tdb | 2440.09 | LIQUID (x(O) 0.50447) + ION (x(O) 0.5185) + X_R2O3 (x(O) 0.57468) |
| CeO-08Dju.tdb | 2416.14 | CE62O112 (x(O) 0.64368) + CE11O20 (x(O) 0.64516) + GAS (x(O) 1) |
| CeO-08Dju.tdb | 2412.9 | LIQUID (x(O) 0.47388) + X_R2O3 (x(O) 0.57395) + H_R2O3 (x(O) 0.57419) |
| CeO-08Dju.tdb | 2361.24 | LIQUID (x(O) 0.63143) + CE19O34 (x(O) 0.64151) + CE40O72 (x(O) 0.64286) |
| CeO-08Dju.tdb | 1692.18 | ION (x(O) 0.0372) + LIQUID (x(O) 0.05324) + H_R2O3 (x(O) 0.57993) |
| CeO-08Dju.tdb | 1684.13 | ION (x(O) 0.03625) + X_R2O3 (x(O) 0.52354) + H_R2O3 (x(O) 0.58012) |
| CeO-08Dju.tdb | 1081.23 | ION (x(O) 0.00131) + BCC_A2 (x(O) 0.00647) + X_R2O3 (x(O) 0.50116) |
| CeO-08Dju.tdb | 1005.61 | BCC_A2 (x(O) 0.00352) + FCC_A1 (x(O) 0.0055) + X_R2O3 (x(O) 0.50069) |
| CeO-08Dju.tdb | 435.98 | CE19O34 (x(O) 0.64151) + CE40O72 (x(O) 0.64286) + CE62O112 (x(O) 0.64368) |
| CeO-08Dju.tdb | 431.2 | CE19O34 (x(O) 0.64151) + CE62O112 (x(O) 0.64368) + CE11O20 (x(O) 0.64516) |
| CeO-08Dju.tdb | 420.08 | CE9O16 (x(O) 0.64) + CE19O34 (x(O) 0.64151) + CE11O20 (x(O) 0.64516) |
| CeO-08Dju.tdb | 398.92 | CE7O12 (x(O) 0.63158) + CE9O16 (x(O) 0.64) + CE11O20 (x(O) 0.64516) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/CE/CE-O.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/CE/CE-O.json) · [CALPHAD hull CeO-06Zin](https://data.orchid-project.org/hulls/calphad-sgte/CE/CE-O--CeO-06Zin.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Ce–O system (48)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 4110 | congruent melting: L->gas (P=1 bar) | L: O 0.608; gas: O 0.608 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 1; `ORC-QVM57ES4YI` |  |
| 3299 | congruent melting: L->gas (P=1 bar) | L: O 0.456; gas: O 0.456 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 2; `ORC-QHOC77UZQC` |  |
| 2566 | peritectic: F=L+gas (P=1 bar) | F: O 0.649; L: O 0.637 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 3; `ORC-MTLW62QAD5` |  |
| 2557 | peritectic: CeO2(F)->L+gas (P=1 bar) | L: O 0.637; F: O 0.649 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 3; `ORC-JZVWZFMETZ` |  |
| 2532 | congruent melting: L->Ce2O3(X) | L: O 0.582; X: O 0.582 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 4; `ORC-WU2V7BAWSQ` |  |
| 2413 | metatectic/catatectic: L+Ce2O3(X)->Ce2O3(H) | L: O 0.601 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 5; `ORC-L5ZOKY4YM5` |  |
| 2413 | metatectic/catatectic: L+Ce2O3(X)->Ce2O3(H) | L: O 0.474 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 6; `ORC-MHKF2TPNJ4` |  |
| 2413 | metatectic/catatectic: L+X=H | L: O 0.601; X: O 0.593; H: O 0.593 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 5; `ORC-YG6VFEEP3Z.3699e5` |  |
| 2413 | metatectic/catatectic: L+X=H | L: O 0.52; X: O 0.572; H: O 0.572 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 6; `ORC-YG6VFEEP3Z.f0359d` |  |
| 2338 | metatectic/catatectic: L+Ce2O3(H)->Ce2O3(A) | L: O 0.603 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 7; `ORC-65OBDLNBQM` |  |
| 2338 | metatectic/catatectic: L+Ce2O3(H)->Ce2O3(A) | L: O 0.359 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 8; `ORC-FGV2AKDKDC` |  |
| 2338 | metatectic/catatectic: L+H=A | L: O 0.603; H: O 0.596; A: O 0.596 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 7; `ORC-HJBUI66DXK.9551c3` |  |
| 2338 | metatectic/catatectic: L+H=A | L: O 0.337; H: O 0.569; A: O 0.569 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 8; `ORC-HJBUI66DXK.ff0fce` |  |
| 2079 | eutectic: L->Ce2O3(A)+CeO2(F) | L: O 0.615; A: O 0.6; F: O 0.623 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 9; `ORC-LPFNZX2YIA` |  |
| 2076 | eutectic: L=A+F | L: O 0.614; A: O 0.6; F: O 0.623 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 9; `ORC-FN2ZCQQ3SD` |  |
| 1676 | peritectoid: A+F=C | A: O 0.6; F: O 0.629; C: O 0.622 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 10; `ORC-MURQT75IQW` |  |
| 1321 | peritectoid: C+F=Ce7O12 | C: O 0.628; F: O 0.635 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 11; `ORC-62EQBGD3RR` |  |
| 1296 | peritectoid: C+F=Ce7O12 |  | experimental | [2] ZINKEVICH 2006; _cites Bevan 1964_ [doi](https://doi.org/10.1016/0022-1902%2864%2980038-5) | Table 5, p. 9, row 12; `ORC-K4P5MEKDXK` |  |
| 1084 | peritectoid: C+F=Ce7O12 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 13; `ORC-4RQCZ2L4RQ` |  |
| 1080 | peritectic: L+A=bcc-Ce | L: O 0.0011; A: O 0.598; bcc-Ce: O 0.0057 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 40; `ORC-AIY7A3NYET` |  |
| 1080 | peritectic: L+Ce2O3(A)->δ-Ce(bcc) | L: O 0.0011; A: O 0.598; bcc: O 0.0057 | unspecified | [1] DJUROVIC 2008 | Table 4, p. 6, row 10; `ORC-DEZAP6TBYF` |  |
| 1072 | peritectoid: C+F=Ce7O12 |  | experimental | [2] ZINKEVICH 2006; _cites Kummerle 2000_ [doi](https://doi.org/10.1006/jssc.2000.8745) | Table 5, p. 9, row 14; `ORC-R434SVKTIN` |  |
| 1005 | peritectoid: bcc-Ce+A=fcc-Ce | bcc-Ce: O 0.0031; A: O 0.598; fcc-Ce: O 0.0049 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 41; `ORC-OBY3ZEGKHU` |  |
| 952 | peritectoid: Ce7O12+F=Ce9O16 |  | experimental | [2] ZINKEVICH 2006; _cites Tuller 1977_ [doi](https://doi.org/10.1016/0022-3697%2877%2990124-x) | Table 5, p. 9, row 18; `ORC-UDDDSUBMHQ` |  |
| 930 | congruent transformation: F=F′+Fʺ | F: O 0.6586; F′: O 0.6586; Fʺ: O 0.6586 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 39; `ORC-MY5MOVS4IQ` |  |
| 913 | peritectoid: Ce7O12+F=Ce9O16 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 19; `ORC-KBHILNUKEU` |  |
| 911 | peritectoid: Ce7O12+F=Ce9O16 |  | experimental | [2] ZINKEVICH 2006; _cites Kummerle 2000_ [doi](https://doi.org/10.1006/jssc.2000.8745) | Table 5, p. 9, row 21; `ORC-VNFLJ73MFR` |  |
| 905 | peritectoid: Ce7O12+F=Ce9O16 | F: O 0.641 | experimental | [2] ZINKEVICH 2006; _cites Korner 1989_ | Table 5, p. 9, row 20; `ORC-MLO3NMCC2Y` |  |
| 905 | peritectoid: Ce7O12+F=Ce9O16 | F: O 0.64003 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 17; `ORC-XNRKMHKHJ2` |  |
| 898 | peritectoid: Ce9O16+F=Ce19O34 |  | experimental | [2] ZINKEVICH 2006; _cites Kummerle 2000_ [doi](https://doi.org/10.1006/jssc.2000.8745) | Table 5, p. 9, row 24; `ORC-WH47KKDRFC` |  |
| 885 | eutectoid: C=A+Ce7O12 | C: O 0.622; A: O 0.6 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 15; `ORC-K3VE3NM5NJ` |  |
| 880 | peritectoid: Ce9O16+F=Ce19O34 | F: O 0.64154 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 22; `ORC-5FH3CQP3IV` |  |
| 880 | peritectoid: Ce9O16+F=Ce19O34 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 23; `ORC-RJAJOVSPJG` |  |
| 873 | eutectoid: C=A+Ce7O12 |  | experimental | [2] ZINKEVICH 2006; _cites Bevan 1964_ [doi](https://doi.org/10.1016/0022-1902%2864%2980038-5) | Table 5, p. 9, row 16; `ORC-S34XKVRYPW` |  |
| 866 | peritectoid: Ce19O34+F=Ce40O72 |  | experimental | [2] ZINKEVICH 2006; _cites Kummerle 2000_ [doi](https://doi.org/10.1006/jssc.2000.8745) | Table 5, p. 9, row 28; `ORC-Q7QIME4Y7W` |  |
| 860 | peritectoid: Ce19O34+F=Ce40O72 | F: O 0.645 | experimental | [2] ZINKEVICH 2006; _cites Korner 1989_ | Table 5, p. 9, row 27; `ORC-H33VSEWPMI` |  |
| 855 | peritectoid: Ce19O34+F=Ce40O72 | F: O 0.6431 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 25; `ORC-3YTCHTED7J` |  |
| 850 | peritectoid: Ce19O34+F=Ce40O72 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 26; `ORC-KEZWZUEMAF` |  |
| 766 | peritectoid: Ce40O72+F=Ce62O112 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 30; `ORC-565NLTMOA2` |  |
| 760 | peritectoid: Ce40O72+F=Ce62O112 | F: O 0.64647 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 29; `ORC-HPORYSM46Z` |  |
| 756 | peritectoid: Ce40O72+F=Ce62O112 | F: O 0.647 | experimental | [2] ZINKEVICH 2006; _cites Korner 1989_ | Table 5, p. 9, row 31; `ORC-CTBQNWPBVY` |  |
| 755 | peritectoid: Ce40O72+F=Ce62O112 |  | experimental | [2] ZINKEVICH 2006; _cites Kummerle 2000_ [doi](https://doi.org/10.1006/jssc.2000.8745) | Table 5, p. 9, row 32; `ORC-32OX5EJYXM` |  |
| 736 | peritectoid: Ce62O112+F=Ce11O20 |  | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 34; `ORC-SVGDGCQNWE` |  |
| 732 | peritectoid: Ce62O112+F=Ce11O20 | F: O 0.64736 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 33; `ORC-7FS4JISPHA` |  |
| 725 | peritectoid: Ce62O112+F=Ce11O20 | F: O 0.648 | experimental | [2] ZINKEVICH 2006; _cites Korner 1989_ | Table 5, p. 9, row 35; `ORC-UGWYDDZ67Z` |  |
| 722 | eutectoid: F′=Fʺ+Ce11O20 | F′: O 0.6486; Fʺ: O 0.666 | experimental | [2] ZINKEVICH 2006; _cites Ricken 1984_ [doi](https://doi.org/10.1016/0022-4596%2884%2990135-x) | Table 5, p. 9, row 37; `ORC-36QZMTL3IF` |  |
| 721 | eutectoid: F′=Fʺ+Ce11O20 | F′: O 0.64802; Fʺ: O 0.66504 | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 36; `ORC-MK6UJOGAI3` |  |
| 714 | eutectoid: F′=Fʺ+Ce11O20 |  | experimental | [2] ZINKEVICH 2006; _cites Korner 1989_ | Table 5, p. 9, row 38; `ORC-P5CZBI4EI6` |  |

## 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, Ce–O system (1)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| A-Ce2O3 | [Ce2O3](https://data.orchid-project.org/compounds/Ce2O3.html) | -358.476 kJ/mol-atom | 298.15 | model | -363.729 (mp-aaabewgf) | -339.664 (oqmd-16544) | [3] ZINKEVICH 2007 | Table 6.1, p. 24, row 19; `ORC-4HKVPHGJ7S.36bcc7` |  |

## Other properties

### Phase transition (6)

Table: Phase transition, Ce–O system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 2338 K | 2338 | polymorphic: A \<=> H; _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 2.2, p. 8, row 11; `ORC-NO7EXNXG6V` |  |
| Phase transition | 2413 K | 2413 | polymorphic: H \<=> X; _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 2.2, p. 8, row 25; `ORC-REI7WZMZIZ` |  |
| Phase transition | 2500 K | 2500 | congruent melting: L=X; _L: O 0.583; X: O 0.583_ | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 4; `ORC-5O3SHZB3JT` |  |
| Phase transition | 3000 K | 3000 | congruent transformation | model | [2] ZINKEVICH 2006 | p. 12; `ORC-RRHEYMPBLM` | “While present work accumulates all previous knowledge about the Ce-O system, several new results were also obtained: 1) Probable value for the melting point of the stoichiometric CeO2 (3000 ± 20 K). The melting is congruent only under elevated pressure.” |
| Phase transition | 3306 K | 3306 | congruent melting: L=gas (P=1 bar); _L: O 0.456; gas: O 0.456_ | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 2; `ORC-4Z6HARMKC5` |  |
| Phase transition | 4111 K | 4111 | congruent melting: L=gas (P=1 bar); _L: O 0.608; gas: O 0.608_ | model | [2] ZINKEVICH 2006 | Table 5, p. 9, row 1; `ORC-CHMVPK6OK6` |  |

### Phase equilibrium (12)

Table: Phase equilibrium, Ce–O system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase composition |  | 2415 | other: Ce2O3; _liquid: O 0.6_ | experimental | [2] ZINKEVICH 2006; _cites Mordovin 1967_ | Table 3, p. 4, row 2; `ORC-ATTJOVBAFL` |  |
| Phase composition |  | 2433 | other: Ce2O3; _liquid: O 0.6_ | experimental | [2] ZINKEVICH 2006; _cites Leonov 1966_ | Table 3, p. 4, row 1; `ORC-QYVDPKD5JH` |  |
| Phase composition |  | 2483 | other: Ce2O3; _liquid: O 0.6_ | experimental | [2] ZINKEVICH 2006; _cites Sata 1968_ | Table 3, p. 4, row 3; `ORC-THKS6FIYYF` |  |
| Phase composition |  | 2513 | other: Ce2O3; _liquid: O 0.6_ | experimental | [2] ZINKEVICH 2006; _cites Shevthenko 1985_ | Table 3, p. 4, row 5; `ORC-BMLXKQZUID` |  |
| Phase composition |  | 2513 | other: Ce2O3; _liquid: O 0.6_ | experimental | [2] ZINKEVICH 2006; _cites Tresvyatskii 1971_ | Table 3, p. 4, row 4; `ORC-JGSECTEIS5` |  |
| Phase composition |  | 2670 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Mordovin 1967_ | Table 3, p. 4, row 12; `ORC-F7QUUOU7TT` |  |
| Phase composition |  | 2753 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Foex 1966_ | Table 3, p. 4, row 11; `ORC-LYTLSL5TCO` |  |
| Phase composition |  | 2998 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Samsonov 1961_ | Table 3, p. 4, row 9; `ORC-KYBL6EQ7CI` |  |
| Phase composition |  | 3000 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Brewer 1953_ | Table 3, p. 4, row 7; `ORC-OUEXMUGVAJ` |  |
| Phase composition |  | 3023 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Ryskewitch 1960_ | Table 3, p. 4, row 8; `ORC-BOZMAAQGKP` |  |
| Phase composition |  | 3023 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Tresvyatkii 1964_ | Table 3, p. 4, row 10; `ORC-CQ7EYVAKAY` |  |
| Phase composition |  | 3073 | other: CeO2; _liquid: O 0.666667_ | experimental | [2] ZINKEVICH 2006; _cites Trombe 2006_ | Table 3, p. 4, row 6; `ORC-RB2CAAOOZR` |  |

### Heat capacity / entropy / enthalpy (1)

Table: Heat capacity / entropy / enthalpy, Ce–O system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: °S_ | 148.8 unknown | 298.15 | A-Ce2O3; _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 6.1, p. 24, row 19; `ORC-4HKVPHGJ7S.15a4f6` |  |

### Crystal structure (22)

Table: Crystal structure, Ce–O system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 0.6757 not_printed ± 3.000e-4 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.3c1a20` |  |
| Lattice a | 0.6627 not_printed | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.c340a0` |  |
| Lattice a | 0.3891 not_printed ± 1.000e-4 | 298.15 | Ce2O3-x (A) | experimental | [2] ZINKEVICH 2006; _cites Barnigshausen 1985_ | Table 1, p. 2, row 1; `ORC-RNBQGINQDQ.f2c0e6` |  |
| Lattice a | 0.6785 not_printed ± 1.000e-4 | 298.15 | Ce7O12; _alloy: Ce 0.368421, O 0.631579_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 3; `ORC-NT4RADPSWZ.6380aa` |  |
| Lattice a | 6.785 Å ± 0.001 | 298.15 | Ce7O12; _alloy: Ce 0.368421, O 0.631579_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 11; `ORC-Y2GBJKXBG3.120868` |  |
| Lattice a | 5.4112 not_printed ± 0.001 | 298.15 | CeO2-x (F) | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 9; `ORC-ZYBFCZ7W4V` |  |
| Lattice b | 1.026 not_printed ± 5.000e-4 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.c34d95` |  |
| Lattice b | 1.1478 not_printed | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.96f0f9` |  |
| Lattice c | 0.6732 not_printed ± 3.000e-4 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.a99cc3` |  |
| Lattice c | 1.0123 not_printed | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.eeed1a` |  |
| Lattice c | 0.6059 not_printed ± 1.000e-4 | 298.15 | Ce2O3-x (A) | experimental | [2] ZINKEVICH 2006; _cites Barnigshausen 1985_ | Table 1, p. 2, row 1; `ORC-RNBQGINQDQ.d9fe6b` |  |
| lattice alpha | 99.42 ° ± 0.01 | 298.15 | Ce7O12; _alloy: Ce 0.368421, O 0.631579_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 11; `ORC-Y2GBJKXBG3.6b1f53` |  |
| lattice molar volume | 47.842 cm3 mol-1 | 298.15 | Ce2O3 (A-type); _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 3.1, p. 12, row 4; `ORC-IXCB5BHGGE.21f0f2` |  |
| lattice molar volume | 48.985 cm3 mol-1 | 298.15 | Ce2O3 (B-type); _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 3.1, p. 12, row 4; `ORC-IXCB5BHGGE.88ef67` |  |
| lattice molar volume | 53.637 cm3 mol-1 | 298.15 | Ce2O3 (C-type); _alloy: O 0.6_ | model | [3] ZINKEVICH 2007 | Table 3.1, p. 12, row 4; `ORC-IXCB5BHGGE.a3373e` |  |
| lattice unspecified angle | 96.22 ° ± 0.04 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.06f95a` |  |
| lattice unspecified angle | 99.8 ° ± 0.04 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.4f693d` |  |
| lattice unspecified angle | 90.04 ° ± 0.04 | 298.15 | Ce11O20; _alloy: Ce 0.354839, O 0.645161_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 8; `ORC-BVB7LPHSYP.e8f117` |  |
| lattice unspecified angle | 100.9 ° | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.dc499e` |  |
| lattice unspecified angle | 90 ° | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.de1cd3` |  |
| lattice unspecified angle | 95.5 ° | 298.15 | Ce19O34; _alloy: Ce 0.358491, O 0.641509_ | experimental | [2] ZINKEVICH 2006; _cites Knappe 1985_ | Table 1, p. 2, row 5; `ORC-MKMKVUWWC4.e6bfb9` |  |
| lattice unspecified angle | 99.42 ° ± 0.01 | 298.15 | Ce7O12; _alloy: Ce 0.368421, O 0.631579_ | experimental | [2] ZINKEVICH 2006; _cites Kummerle 1999_ | Table 1, p. 2, row 3; `ORC-NT4RADPSWZ.1503e3` |  |

## Sources

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

1. D DJUROVIC, M ZINKEVICH, F ALDINGER, Thermodynamic modeling of the cerium–yttrium–oxygen system, Solid State Ionics 179, 1902-1911 (2008). [doi:10.1016/j.ssi.2008.06.011](https://doi.org/10.1016/j.ssi.2008.06.011)
2. M ZINKEVICH, D DJUROVIC, F ALDINGER, Thermodynamic modelling of the cerium–oxygen system☆, Solid State Ionics 177, 989-1001 (2006). [doi:10.1016/j.ssi.2006.02.044](https://doi.org/10.1016/j.ssi.2006.02.044)
3. M ZINKEVICH, Thermodynamics of rare earth sesquioxides, Progress in Materials Science 52, 597-647 (2007). [doi:10.1016/j.pmatsci.2006.09.002](https://doi.org/10.1016/j.pmatsci.2006.09.002)

## 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-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735859
- 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); 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).

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_phase_diagrams_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Diagrams: calculated binary phase diagrams}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735859},
  url       = {https://doi.org/10.5281/zenodo.23735859}
}

@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/).