# Fe–U system

> Fe–U system: 70 accepted literature values (formation 33, invariant reaction 30, crystal structure 3, activity / EMF / Gibbs energy 2) and 4 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/FE-U.html · Markdown: https://data.orchid-project.org/systems/FE-U.md

70 accepted literature values from 2 paper(s) (experimental 32, model 33, unspecified 5); 4 calculated phase diagram(s). 8 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/FE-U.json) · [CSV](https://data.orchid-project.org/systems/FE-U.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#FE-U) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#FE-U/FeU-03Cha.json) · [phases (8)](https://data.orchid-project.org/phases/pages/FE-U.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/FE-U.html) · [Markdown](https://data.orchid-project.org/systems/FE-U.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 32 |
| model | 33 |
| unspecified | 5 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 30 |
| phase transition | 2 |
| formation | 33 |
| activity / EMF / Gibbs energy | 2 |
| crystal structure | 3 |

## 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 |
|---|---|---|---|
| FeU-03Cha.tdb | S. Chatain, C. Gueneau, D. Labroche, J. Rogez, O. Dugne, J. Phase Equilib., 24, 122-31(2003). [doi:10.1361/105497103770330730](https://doi.org/10.1361/105497103770330730) | `2b3cb4ca0291ed3cec49faea394963700e207a689d4e2669ea1bf1da911adea9` | [viewer](https://orchid-project.org/phase-diagrams/#FE-U/FeU-03Cha.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/FeU-03Cha.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/FeU-03Cha.json) |
| FeU-10Kur.tdb | M. Kurata, IOP Conf. Ser.: Mater. Sci. Eng., 9, 012023(2010). | `bc15fcbedb33d3b61b1207f0bb6fae978c164b78fc1705c9750db8401fdc214d` | [viewer](https://orchid-project.org/phase-diagrams/#FE-U/FeU-10Kur.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/FeU-10Kur.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/FeU-10Kur.json) |
| FeU-23Jia.tdb | Y. Jiang, Y. He, W. Zheng, J. Zhang, D. Zhang, X. Lu, J. Nucl. Mater., 574, 154180(2023). [doi:10.1016/j.jnucmat.2022.154180](https://doi.org/10.1016/j.jnucmat.2022.154180) | `eb9a00d844e17ebb775573d55afbaedddf4b75254b5ba94855c3b473cfd410fb` | [viewer](https://orchid-project.org/phase-diagrams/#FE-U/FeU-23Jia.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/FeU-23Jia.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/FeU-23Jia.json) |
| FeU-98Kur.tdb | M. Kurata, T. Ogata, K. Nakamura, T. Ogawa, J. Alloys Compd., 271-273, 636-40(1998). [doi:10.1016/S0925-8388(98)00176-5](https://doi.org/10.1016/S0925-8388%2898%2900176-5) | `d4682ee275bf4ce8df794fbf2ac24bedb60801d70b4ce2bb78eb04d0dee9d56e` | [viewer](https://orchid-project.org/phase-diagrams/#FE-U/FeU-98Kur.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/FeU-98Kur.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/FeU-98Kur.json) |

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

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| FeU-03Cha.tdb | 1667.47 | BCC_A2 (x(U) 0) + FCC_A1 (x(U) 0) + LIQUID (x(U) 0.06522) |
| FeU-03Cha.tdb | 1667.47 | FCC_A1 (x(U) 0) + BCC_A2 (x(U) 0) + LIQUID (x(U) 0.06508) |
| FeU-03Cha.tdb | 1351.07 | FCC_A1 (x(U) 0) + LIQUID (x(U) 0.17463) + FE2U_C15 (x(U) 0.33333) |
| FeU-03Cha.tdb | 1351.06 | FCC_A1 (x(U) 0) + LIQUID (x(U) 0.17453) + FE2U_C15 (x(U) 0.33333) |
| FeU-03Cha.tdb | 1351.06 | FCC_A1 (x(U) 0) + LIQUID (x(U) 0.17455) + FE2U_C15 (x(U) 0.33333) |
| FeU-03Cha.tdb | 1184.81 | FCC_A1 (x(U) 0) + BCC_A2 (x(U) 0) + FE2U_C15 (x(U) 0.33333) |
| FeU-03Cha.tdb | 1012.62 | LIQUID (x(U) 0.81648) + BCC_A2 (x(U) 0.9849) + TETRAGONAL_U (x(U) 0.99884) |
| FeU-03Cha.tdb | 938.79 | LIQUID (x(U) 0.77537) + TETRAGONAL_U (x(U) 0.99878) + ORTHORHOMBIC_A20 (x(U) 1) |
| FeU-03Cha.tdb | 938.79 | LIQUID (x(U) 0.77535) + TETRAGONAL_U (x(U) 0.99878) + ORTHORHOMBIC_A20 (x(U) 1) |
| FeU-03Cha.tdb | 886.24 | LIQUID (x(U) 0.74214) + FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) |
| FeU-03Cha.tdb | 886.24 | LIQUID (x(U) 0.74209) + FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) |
| FeU-03Cha.tdb | 886.24 | LIQUID (x(U) 0.74232) + FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) |
| FeU-03Cha.tdb | 875.01 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.71754) + FEU6_D2C (x(U) 0.85714) |
| FeU-03Cha.tdb | 875.01 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.71736) + FEU6_D2C (x(U) 0.85714) |
| FeU-10Kur.tdb | 1656.15 | FCC_A1 (x(U) 0.00188) + BCC_A2 (x(U) 0.00228) + LIQUID (x(U) 0.06914) |
| FeU-10Kur.tdb | 1352.33 | FCC_A1 (x(U) 0.00596) + LIQUID (x(U) 0.16976) + FE2U_C15 (x(U) 0.33333) |
| FeU-10Kur.tdb | 1352.33 | FCC_A1 (x(U) 0.00596) + LIQUID (x(U) 0.16975) + FE2U_C15 (x(U) 0.33333) |
| FeU-10Kur.tdb | 1183.38 | BCC_A2 (x(U) 0.0024) + FCC_A1 (x(U) 0.00252) + FE2U_C15 (x(U) 0.33333) |
| FeU-10Kur.tdb | 1183.38 | BCC_A2 (x(U) 0.00234) + FCC_A1 (x(U) 0.00246) + FE2U_C15 (x(U) 0.33333) |
| FeU-10Kur.tdb | 1075.51 | LIQUID (x(U) 0.80905) + FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.98861) |
| FeU-10Kur.tdb | 1075.51 | LIQUID (x(U) 0.80908) + FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.98861) |
| FeU-10Kur.tdb | 1035.69 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.99299) + TETRAGONAL_U (x(U) 1) |
| FeU-10Kur.tdb | 1035.69 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.99297) + TETRAGONAL_U (x(U) 1) |
| FeU-10Kur.tdb | 998.06 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.68841) + FEU6_D2C (x(U) 0.85714) |
| FeU-10Kur.tdb | 998.06 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.68826) + FEU6_D2C (x(U) 0.85714) |
| FeU-10Kur.tdb | 942.02 | FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) + TETRAGONAL_U (x(U) 1) |
| FeU-23Jia.tdb | 1676.75 | BCC_A2 (x(U) 0.0016) + FCC_A1 (x(U) 0.00193) + LIQUID (x(U) 0.05845) |
| FeU-23Jia.tdb | 1394.59 | FCC_A1 (x(U) 0.00719) + LIQUID (x(U) 0.15566) + FE2U_C15 (x(U) 0.33333) |
| FeU-23Jia.tdb | 1394.59 | FCC_A1 (x(U) 0.00719) + LIQUID (x(U) 0.15563) + FE2U_C15 (x(U) 0.33333) |
| FeU-23Jia.tdb | 1176.56 | BCC_A2 (x(U) 0.00164) + FCC_A1 (x(U) 0.00238) + FE2U_C15 (x(U) 0.33333) |
| FeU-23Jia.tdb | 1176.56 | BCC_A2 (x(U) 0.00163) + FCC_A1 (x(U) 0.00236) + FE2U_C15 (x(U) 0.33333) |
| FeU-23Jia.tdb | 1083.21 | FEU6_D2C (x(U) 0.85714) + LIQUID (x(U) 0.85936) + BCC_A2 (x(U) 0.97987) |
| FeU-23Jia.tdb | 1083.21 | FEU6_D2C (x(U) 0.85714) + LIQUID (x(U) 0.85936) + BCC_A2 (x(U) 0.97987) |
| FeU-23Jia.tdb | 1028.4 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.98931) + TETRAGONAL_U (x(U) 1) |
| FeU-23Jia.tdb | 1028.4 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.98931) + TETRAGONAL_U (x(U) 1) |
| FeU-23Jia.tdb | 1017.81 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.71714) + FEU6_D2C (x(U) 0.85714) |
| FeU-23Jia.tdb | 942.02 | FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) + TETRAGONAL_U (x(U) 1) |
| FeU-98Kur.tdb | 1643.64 | FCC_A1 (x(U) 0.00178) + BCC_A2 (x(U) 0.00262) + LIQUID (x(U) 0.07346) |
| FeU-98Kur.tdb | 1352.21 | FCC_A1 (x(U) 0.00596) + LIQUID (x(U) 0.17194) + FE2U_C15 (x(U) 0.33333) |
| FeU-98Kur.tdb | 1352.21 | FCC_A1 (x(U) 0.00596) + LIQUID (x(U) 0.1719) + FE2U_C15 (x(U) 0.33333) |
| FeU-98Kur.tdb | 1194.39 | FCC_A1 (x(U) 0.00308) + BCC_A2 (x(U) 0.00389) + FE2U_C15 (x(U) 0.33333) |
| FeU-98Kur.tdb | 1194.38 | FCC_A1 (x(U) 0.00312) + BCC_A2 (x(U) 0.00394) + FE2U_C15 (x(U) 0.33333) |
| FeU-98Kur.tdb | 1083.01 | LIQUID (x(U) 0.83206) + FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.98409) |
| FeU-98Kur.tdb | 1032.44 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.99128) + TETRAGONAL_U (x(U) 1) |
| FeU-98Kur.tdb | 1032.44 | FEU6_D2C (x(U) 0.85714) + BCC_A2 (x(U) 0.99126) + TETRAGONAL_U (x(U) 1) |
| FeU-98Kur.tdb | 998.07 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.68427) + FEU6_D2C (x(U) 0.85714) |
| FeU-98Kur.tdb | 998.07 | FE2U_C15 (x(U) 0.33333) + LIQUID (x(U) 0.68424) + FEU6_D2C (x(U) 0.85714) |
| FeU-98Kur.tdb | 942.02 | FEU6_D2C (x(U) 0.85714) + ORTHORHOMBIC_A20 (x(U) 1) + TETRAGONAL_U (x(U) 1) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/FE/FE-U.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/FE/FE-U.json) · [CALPHAD hull FeU-03Cha](https://data.orchid-project.org/hulls/calphad-sgte/FE/FE-U--FeU-03Cha.json) · [CALPHAD hull FeU-10Kur](https://data.orchid-project.org/hulls/calphad-sgte/FE/FE-U--FeU-10Kur.json) · [CALPHAD hull FeU-98Kur](https://data.orchid-project.org/hulls/calphad-sgte/FE/FE-U--FeU-98Kur.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Fe–U system (30)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 1673 | L + bcc - Fe \<-> fcc - Fe |  | experimental | [1] Chatain 2003; _cites Michaud 1966_ [doi](https://doi.org/10.1179/cmq.1966.5.4.355) | Table 6, p. 8, row 1; `ORC-75WGNWJ55O` |  |
| 1667 | L + bcc - Fe \<-> fcc - Fe |  | model | [1] Chatain 2003 | Table 6, p. 8, row 2; `ORC-ORHUIQEVIG` |  |
| 1509 | congruent melting: L \<-> Fe2U | L: Fe 0.666667, U 0.333333; Fe2U: Fe 0.666667, U 0.333333 | model | [1] Chatain 2003 | Table 6, p. 8, row 13; `ORC-6BV2G7LXXZ` |  |
| 1508 | congruent melting: L \<-> Fe2U | L: Fe 0.666667, U 0.333333; Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Michaud 1966_ [doi](https://doi.org/10.1179/cmq.1966.5.4.355) | Table 6, p. 8, row 9; `ORC-HQTMWYX3BZ` |  |
| 1507 | congruent melting: L \<-> Fe2U | L: Fe 0.666667, U 0.333333; Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Labroche 2000_ | Table 6, p. 8, row 10; `ORC-XU4TL2U24U` |  |
| 1503 | congruent melting: L \<-> Fe2U | L: Fe 0.666667, U 0.333333; Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Grogan 1950_ | Table 6, p. 8, row 11; `ORC-GNXJRBP2LZ` |  |
| 1501 | congruent melting: L \<-> Fe2U | L: Fe 0.666667, U 0.333333; Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 12; `ORC-4AXXTIQLZE` |  |
| 1353 | eutectic: L \<-> fcc - Fe + Fe2U | L: U 0.17; Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 3; `ORC-PGKUKSD5JP` |  |
| 1351 | eutectic: L \<-> fcc - Fe + Fe2U | L: U 0.1745; Fe2U: Fe 0.666667, U 0.333333 | model | [1] Chatain 2003 | Table 6, p. 8, row 4; `ORC-ZJ6QZWBB7N` |  |
| 1198 | fcc - Fe + Fe2U \<-> bcc - Fe | Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Leibowitz 1991_ [doi](https://doi.org/10.1016/0022-3115%2891%2990531-b) | Table 6, p. 8, row 7; `ORC-3KIDPT4HS2` |  |
| 1185 | fcc - Fe + Fe2U \<-> bcc - Fe | Fe2U: Fe 0.666667, U 0.333333 | model | [1] Chatain 2003 | Table 6, p. 8, row 8; `ORC-I3X54MEQ4Q` |  |
| 1183 | fcc - Fe + Fe2U \<-> bcc - Fe | Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 6; `ORC-5OAVKGCPX7` |  |
| 1182 | fcc - Fe + Fe2U \<-> bcc - Fe | Fe2U: Fe 0.666667, U 0.333333 | experimental | [1] Chatain 2003; _cites Michaud 1966_ [doi](https://doi.org/10.1179/cmq.1966.5.4.355) | Table 6, p. 8, row 5; `ORC-6OSNVF5FMD` |  |
| 1104 | peritectic: L + bcc - U \<-> FeU6 | L: U 0.8494; FeU6: Fe 0.142857, U 0.857143; bcc-U: U 0.9865 | model | [1] Chatain 2003 | Table 6, p. 8, row 20; `ORC-KEDRRKTUZW` |  |
| 1104 | peritectic |  | model | [1] Chatain 2003 | p. 7; `ORC-RRBKLFGK42` | “The calculated peritectic transformation temperature is equal to 1104 K for a liquid uranium content of 84.94 at.%.” |
| 1102 | peritectic: L + bcc - U \<-> FeU6 | FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Labroche 2000_ | Table 6, p. 8, row 19; `ORC-SHWVCWZWXY` |  |
| 1102 | peritectic |  | experimental | [1] Chatain 2003 | p. 7; `ORC-SYKCTJ3YXT` | “Labroche's FeU6 peritectic temperature of 1102 K was measured by calorimetry during slow heating with the same apparatus that was used for Fe2U.” |
| 1078 | peritectic: L + bcc - U \<-> FeU6 | L: U 0.85; bcc - U: U 0.985; FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Grogan 1950_ | Table 6, p. 8, row 18; `ORC-PNTHXAGHJB` |  |
| 1039 | bcc - U \<-> tetragonal - U + FeU6 | FeU6: Fe 0.142857, U 0.857143; tetragonal-U: U 0.9954 | model | [1] Chatain 2003 | Table 6, p. 8, row 24; `ORC-6KW4N5GBE4` |  |
| 1036 | bcc - U \<-> tetragonal - U + FeU6 | FeU6: Fe 0.142857, U 0.857143; bcc-U: U 0.992 | experimental | [1] Chatain 2003; _cites Straatmann 1964_ | Table 6, p. 8, row 21; `ORC-W2HI7DEUJQ` |  |
| 1035 | bcc - U \<-> tetragonal - U + FeU6 | FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 22; `ORC-77RFIGA2PF` |  |
| 1034 | bcc - U \<-> tetragonal - U + FeU6 | FeU6: Fe 0.142857, U 0.857143; tetragonal-U: U 0.996 | experimental | [1] Chatain 2003; _cites Grogan 1950_ | Table 6, p. 8, row 23; `ORC-4KHWWPMSDQ` |  |
| 1002 | eutectic: L \<-> Fe2U + FeU6 | Fe2U: Fe 0.666667, U 0.333333; FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Grogan 1950_ | Table 6, p. 8, row 16; `ORC-EA4KWL7QEQ` |  |
| 996 | eutectic: L \<-> Fe2U + FeU6 | L: U 0.66; Fe2U: Fe 0.666667, U 0.333333; FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 15; `ORC-Z4QEHOXYTT` |  |
| 994 | eutectic: L \<-> Fe2U + FeU6 | Fe2U: Fe 0.666667, U 0.333333; FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Leibowitz 1991_ [doi](https://doi.org/10.1016/0022-3115%2891%2990531-b) | Table 6, p. 8, row 14; `ORC-LMZ6BLTDNC` |  |
| 992.5 | eutectic: L \<-> Fe2U + FeU6 | L: U 0.6651; Fe2U: Fe 0.666667, U 0.333333; FeU6: Fe 0.142857, U 0.857143 | model | [1] Chatain 2003 | Table 6, p. 8, row 17; `ORC-K7LPPXI67F` |  |
| 943 | tetragonal - U \<-> FeU6 + orthorhombic - U | FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Grogan 1950_ | Table 6, p. 8, row 27; `ORC-QSZNGBUY4T` |  |
| 942 | tetragonal - U \<-> FeU6 + orthorhombic - U | FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Chapman 1984_ [doi](https://doi.org/10.1016/0022-3115%2884%2990046-1) | Table 6, p. 8, row 25; `ORC-HZZIGJTIHE` |  |
| 941 | tetragonal - U \<-> FeU6 + orthorhombic - U | tetragonal - U: U 0.99825; FeU6: Fe 0.142857, U 0.857143 | experimental | [1] Chatain 2003; _cites Straatmann 1964_ | Table 6, p. 8, row 26; `ORC-MBJG44CRAQ` |  |
| 937.8 | tetragonal - U \<-> FeU6 + orthorhombic - U | tetragonal - U: U 0.9984; FeU6: Fe 0.142857, U 0.857143 | model | [1] Chatain 2003 | Table 6, p. 8, row 28; `ORC-M2MNT4A5JG` |  |

## 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, Fe–U system (21)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Fe0.143U0.857 |  | -20.931 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003 | Table 7, p. 8, row 20; `ORC-7LTO3XUXDK.6c0f84` |  |
| Fe0.143U0.857 |  | -7.312 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003 | Table 7, p. 8, row 17; `ORC-WY6QHZTJPW.94afe4` |  |
| Fe0.143U0.857 |  | -6.75 unspecified ± 1.3 | 298.15 | experimental |  |  | [1] Chatain 2003; _cites Labroche 2000_ | p. 3; `ORC-KDQSOP2EX7` | “For 1 mol Fe0.143U0.857, ⌬H0f (298 K) ⳱ (-6.75 ± 1.3) kJ/mol.” |
| Fe0.143U0.857 |  | -2.33 kJ/mol (basis unstated) ± 0.72 | 298.15 | model |  |  | [1] Chatain 2003; _cites Ivanov 1962_ | Table 7, p. 8, row 18; `ORC-TTQMN7RO73.4fff1b` |  |
| Fe0.66U0.33 |  | -30.08 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Kurata 2003_ | Table 7, p. 8, row 15; `ORC-RCRNRAUCL2.3e7f06` |  |
| Fe0.66U0.33 |  | -20.6 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Campbell 1977_ [doi](https://doi.org/10.1007/bf02642864) | Table 7, p. 8, row 8; `ORC-X55MHENXWS.2cd47e` |  |
| Fe0.66U0.33 |  | -16.3 kJ/mol (basis unstated) ± 0.6 | 298.15 | model |  |  | [1] Chatain 2003; _cites Labroche 2000_ | Table 7, p. 8, row 5; `ORC-VBXKMZ6DZF.444747` |  |
| Fe0.66U0.33 |  | -15.886 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003 | Table 7, p. 8, row 6; `ORC-YH6KSH5EMG.116370` |  |
| Fe0.66U0.33 |  | -14.01 kJ/mol (basis unstated) ± 1.8 | 298.15 | model |  |  | [1] Chatain 2003; _cites Antony 1996_ [doi](https://doi.org/10.1016/0022-3115%2895%2900164-6) | Table 7, p. 8, row 7; `ORC-MK4JLSOV4H.152668` |  |
| Fe0.66U0.33 |  | -10.739 kJ/mol (basis unstated) ± 0.42 | 298.15 | model |  |  | [1] Chatain 2003; _cites Akhachinskiy 1962_ | Table 7, p. 8, row 9; `ORC-7LTITR3YTS.b419b9` |  |
| Fe2U |  | -34.112 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003 | Table 7, p. 8, row 14; `ORC-IV62NRD2EY.0e33ca` |  |
| Fe2U |  | -25.314 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Okamoto 1993_ [doi](https://doi.org/10.1007/bf02668229) | Table 7, p. 8, row 13; `ORC-HCLBHQ4LF6.4264b3` |  |
| Fe2U |  | -23.54 kJ/mol (basis unstated) ± 0.45 | 298.15 | model |  |  | [1] Chatain 2003; _cites Kanno 1974_ | Table 7, p. 8, row 10; `ORC-CIRZQSRDRD.64fe30` |  |
| Fe2U |  | -16.922 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003 | Table 7, p. 8, row 11; `ORC-CTC5MS5ZZV.6f0bb8` |  |
| Fe2U | [Fe2U](https://data.orchid-project.org/compounds/Fe2U.html) | -16.3 kJ/mol-atom ± 0.6 | 298.15 | experimental | -9.82 (mp-aaaabfdq) | -8.017 (oqmd-19298) | [1] Chatain 2003; _cites Labroche 2000_ | Table 3, p. 3, row 3; `ORC-SB3XW4RX7Z.0a16cb` |  |
| Fe2U |  | -15.025 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Gardie 1992_ [doi](https://doi.org/10.1016/0022-3115%2892%2990422-h) | Table 7, p. 8, row 12; `ORC-YVE44YNJYL.a555a7` |  |
| Fe2U | [Fe2U](https://data.orchid-project.org/compounds/Fe2U.html) | -14.01 kJ/mol-atom ± 1.8 | 298.15 | experimental | -9.82 (mp-aaaabfdq) | -8.017 (oqmd-19298) | [1] Chatain 2003; _cites Antony 1996_ [doi](https://doi.org/10.1016/0022-3115%2895%2900164-6) | Table 3, p. 3, row 2; `ORC-CN3ILEUCE2.2aaf0a` |  |
| Fe2U | [Fe2U](https://data.orchid-project.org/compounds/Fe2U.html) | -10.74 kJ/mol-atom ± 0.42 | 298.15 | experimental | -9.82 (mp-aaaabfdq) | -8.017 (oqmd-19298) | [1] Chatain 2003; _cites Akhachinskiy 1962_ | Table 3, p. 3, row 1; `ORC-STB5INE33U.082a43` |  |
| FeU6 |  | -26.438 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Okamoto 1993_ [doi](https://doi.org/10.1007/bf02668229) | Table 7, p. 8, row 19; `ORC-XOOMW3BU7D.d7ee3d` |  |
| FeU6 |  | -21.343 kJ/mol (basis unstated) | 298.15 | model |  |  | [1] Chatain 2003; _cites Kurata 2003_ | Table 7, p. 8, row 21; `ORC-IL73XN3XZM.137782` |  |
| FeU6 |  | -6.75 kJ/mol (basis unstated) ± 1.3 | 298.15 | model |  |  | [1] Chatain 2003; _cites Labroche 2000_ | Table 7, p. 8, row 16; `ORC-IZTHDDOKTE.101091` |  |

## Other properties

### Phase transition (2)

Table: Phase transition, Fe–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 1300 K | 1300 | other | experimental | [1] Chatain 2003 | p. 3; `ORC-SMIMDGPRVC` | “For Fe2U, a ␭-type heat capacity anomaly occurs around 1300 K.” |
| Phase transition | 1509 K | 1509 | congruent melting | model | [1] Chatain 2003 | p. 7; `ORC-GJXHACNHLP` | “The calculated congruent melting point of Fe2U is equal to 1509 K, which is consistent with the selected data and very close to Labroche's value.” |

### Formation (12)

Table: Formation, Fe–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -5.4 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998; _cites Leibowitz 1991_ [doi](https://doi.org/10.1016/0022-3115%2891%2990531-b) | Table 1, p. 3, row 6; `ORC-4ZTXCCW6MT` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -14.7 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998; _cites Okamoto 1995_ | Table 1, p. 3, row 5; `ORC-ALCQKNUDAG` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -13 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | unspecified | [2] Kurata 1998; _cites Chiotti 1981_ | Table 1, p. 3, row 4; `ORC-CJVOL7CSNH` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -17.9 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | experimental | [2] Kurata 1998; _cites Gardie 1992_ [doi](https://doi.org/10.1016/0022-3115%2892%2990422-h) | Table 1, p. 3, row 2; `ORC-CVGF3TMBIA` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -20 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | experimental | [2] Kurata 1998; _cites Yoshihara 1974_ [doi](https://doi.org/10.1016/0022-1902%2874%2980014-x) | Table 1, p. 3, row 3; `ORC-K3XXTNUK6P` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -20.1 kJ/mol-atom | 998 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998 | Table 1, p. 3, row 1; `ORC-NNWHGV32EF` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -13.4 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | unspecified | [2] Kurata 1998; _cites Chiotti 1981_ | Table 1, p. 3, row 10; `ORC-357XDIZZRU` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -3.1 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998; _cites Leibowitz 1991_ [doi](https://doi.org/10.1016/0022-3115%2891%2990531-b) | Table 1, p. 3, row 12; `ORC-DGSCG2DR4N` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -18.5 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | experimental | [2] Kurata 1998; _cites Yoshihara 1974_ [doi](https://doi.org/10.1016/0022-1902%2874%2980014-x) | Table 1, p. 3, row 9; `ORC-E35FUXJKCM` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -18.4 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | experimental | [2] Kurata 1998; _cites Gardie 1992_ [doi](https://doi.org/10.1016/0022-3115%2892%2990422-h) | Table 1, p. 3, row 8; `ORC-EQEIUEKF4L` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -15.7 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998; _cites Okamoto 1995_ | Table 1, p. 3, row 11; `ORC-JIG7I5ZCSG` |  |
| Gibbs energy of formation; _printed: Gibbs energy of Fe2U formation_ | -18.8 kJ/mol-atom | 1504 | Fe2U; _alloy: U 0.333333_ | model | [2] Kurata 1998 | Table 1, p. 3, row 7; `ORC-SOIZICWXLT` |  |

### Activity / EMF / Gibbs energy (2)

Table: Activity / EMF / Gibbs energy, Fe–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy; _printed: ⌬G0f (FeU6)_ | -4.43 unspecified ± 0.86 | 998 |  | experimental | [1] Chatain 2003 | p. 3; `ORC-EG7KR2O3AE.fc9775` | “⌬G0f (Fe2U) (kJ/mol) ⳱ (-17.6 ± 1.13) kJ/mol at 1501 K ⌬G0f (FeU6) (kJ/mol) ⳱ (-4.43 ± 0.86) kJ/mol at 998 K” |
| Gibbs energy; _printed: ⌬G0f (Fe2U)_ | -17.6 unspecified ± 1.13 | 1501 |  | experimental | [1] Chatain 2003 | p. 3; `ORC-EG7KR2O3AE.b2db5e` | “⌬G0f (Fe2U) (kJ/mol) ⳱ (-17.6 ± 1.13) kJ/mol at 1501 K ⌬G0f (FeU6) (kJ/mol) ⳱ (-4.43 ± 0.86) kJ/mol at 998 K” |

### Crystal structure (3)

Table: Crystal structure, Fe–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 7.055 Å | 298.15 | Fe2U | unspecified | [1] Chatain 2003; _cites Villars 1991_ | Table 2, p. 3, row 4; `ORC-J34PH26E6Y` |  |
| Lattice a | 10.2499 Å | 298.15 | FeU6 | unspecified | [1] Chatain 2003; _cites Villars 1991_ | Table 2, p. 3, row 5; `ORC-YKWUSZVFKL.972c02` |  |
| Lattice c | 5.25 Å | 298.15 | FeU6 | unspecified | [1] Chatain 2003; _cites Villars 1991_ | Table 2, p. 3, row 5; `ORC-YKWUSZVFKL.935d93` |  |

## Sources

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

1. S. Chatain, C. Guéneau, D. Labroche, O. Dugne, J. Rogez, Thermodynamic assessment of the Fe-U binary system, JPE 24, 122-131 (2003). [doi:10.1361/105497103770330730](https://doi.org/10.1361/105497103770330730)
2. Masaki Kurata, Takanari Ogata, Kinya Nakamura, Toru Ogawa, Thermodynamic assessment of the Fe–U, U–Zr and Fe–U–Zr systems, Journal of Alloys and Compounds 271-273, 636-640 (1998). [doi:10.1016/s0925-8388(98)00176-5](https://doi.org/10.1016/s0925-8388%2898%2900176-5)

## 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-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/).