# Eu–Mg system

> Eu–Mg system: 45 accepted literature values (crystal structure 28, invariant reaction 13, phase transition 4) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/EU-MG.html · Markdown: https://data.orchid-project.org/systems/EU-MG.md

45 accepted literature values from 1 paper(s) (experimental 9, model 8, DFT 28); 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/EU-MG.json) · [CSV](https://data.orchid-project.org/systems/EU-MG.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#EU-MG) · [phases (8)](https://data.orchid-project.org/phases/pages/EU-MG.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/EU-MG.html) · [Markdown](https://data.orchid-project.org/systems/EU-MG.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 9 |
| model | 8 |
| DFT | 28 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 13 |
| phase transition | 4 |
| crystal structure | 28 |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/EU/EU-MG.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/EU/EU-MG.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Eu–Mg system (13)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 848 | peritectic: L + Mg2Eu -> Mg5Eu | L: Mg 0.8458 | model | [1] Tao 2008 | Table 3, p. 4, row 9; `ORC-EMPKKJ6VES` |  |
| 847 | eutectic: L -> Mg17Eu2 + Mg5Eu | L: Mg 0.8545 | model | [1] Tao 2008 | Table 3, p. 4, row 7; `ORC-RM5BE2NROD` |  |
| 846 | peritectic: L + Mg2Eu -> Mg5Eu | L: Mg 0.8434 | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 8; `ORC-P4HD2L3RHB` |  |
| 845 | eutectic: L -> HCP + Mg17Eu2 | L: Mg 0.9934 | model | [1] Tao 2008 | Table 3, p. 4, row 3; `ORC-3SGK6UQR7O` |  |
| 844 | eutectic: L -> HCP + Mg17Eu2 | L: Mg 0.994 | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 1; `ORC-7K4H2IMPVB` |  |
| 842 | eutectic: L -> Mg17Eu2 + Mg5Eu | L: Mg 0.86 | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 6; `ORC-YTHO7ZV5MQ` |  |
| 835 | eutectic: L -> HCP + Mg17Eu2 | L: Mg 0.993 | experimental | [1] Tao 2008; _cites Rokhlin 2003_ [doi](https://doi.org/10.1201/9781482265163) | Table 3, p. 4, row 2; `ORC-CPB66HEM6E` |  |
| 813 | eutectoid: Mg5Eu + Mg2Eu -> Mg4Eu | Mg4Eu: Mg 0.8 | experimental | [1] Tao 2008; _cites Zandbergen 1989_ [doi](https://doi.org/10.1016/0022-5088%2889%2990222-1) | Table 3, p. 4, row 10; `ORC-2MFI7DDEZH` |  |
| 813 | eutectoid: Mg5Eu + Mg2Eu -> Mg4Eu | Mg4Eu: Mg 0.8 | model | [1] Tao 2008 | Table 3, p. 4, row 11; `ORC-3IFNRZS2KW` |  |
| 736 | peritectic: L + Mg2Eu -> MgEu | L: Mg 0.34 | model | [1] Tao 2008 | Table 3, p. 4, row 15; `ORC-JBWOZ5UPTF` |  |
| 736 | peritectic: L + Mg2Eu -> MgEu | L: Mg 0.34 | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 14; `ORC-QWUVB7QBQH` |  |
| 728 | eutectic: L -> MgEu + Eu | L: Mg 0.326 | model | [1] Tao 2008 | Table 3, p. 4, row 17; `ORC-PQ656KM23X` |  |
| 722 | eutectic: L -> MgEu + Eu | L: Mg 0.31 | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 16; `ORC-HBSRDJBM6P` |  |

## Other properties

### Phase transition (4)

Table: Phase transition, Eu–Mg system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 857 K | 857 | congruent melting: L -> Mg17Eu2; _L: Mg 0.8947_ | model | [1] Tao 2008 | Table 3, p. 4, row 5; `ORC-QOBI4L53ZH` |  |
| Phase transition | 864 K | 864 | congruent melting: L -> Mg17Eu2; _L: Mg 0.8947_ | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 4; `ORC-VPKSJ74PNP` |  |
| Phase transition | 990 K | 990 | congruent melting: L -> Mg2Eu; _L: Mg 0.6667_ | model | [1] Tao 2008 | Table 3, p. 4, row 13; `ORC-NWQWHI4NTI` |  |
| Phase transition | 992 K | 992 | congruent melting: L -> Mg2Eu; _L: Mg 0.6667_ | experimental | [1] Tao 2008; _cites Muhlpfordt 1969_ [doi](https://doi.org/10.1016/0022-5088%2869%2990045-9) | Table 3, p. 4, row 12; `ORC-ED3UCT43VI` |  |

### Crystal structure (28)

Table: Crystal structure, Eu–Mg system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 10.4289 Å | 0 | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 4; `ORC-5XDXT7ZE7V.45a4f6` |  |
| Lattice a | 10.49 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Klemm 1964_ [doi](https://doi.org/10.1002/anie.196407043) | Table 1, p. 2, row 5; `ORC-ADGSFIYHCV.d1d0f5` |  |
| Lattice a | 10.493 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Lueken 1985_ [doi](https://doi.org/10.1016/0022-5088%2885%2990174-2) | Table 1, p. 2, row 7; `ORC-KD4PWPC5UA.a4b8da` |  |
| Lattice a | 10.468 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Kripyakevich 1969_ | Table 1, p. 2, row 6; `ORC-WBIRBMGIYD.cce48c` |  |
| Lattice a | 6.379 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Klemm 1964_ [doi](https://doi.org/10.1002/anie.196407043) | Table 1, p. 2, row 13; `ORC-KXWUZVDCT3.1d4026` |  |
| Lattice a | 6.3443 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Buschow 1978_ [doi](https://doi.org/10.1063/1.324939) | Table 1, p. 2, row 15; `ORC-R3MIFFSMZD.d76445` |  |
| Lattice a | 6.3319 Å | 0 | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 12; `ORC-RFZH5N5ZUE.1a04ee` |  |
| Lattice a | 6.344 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Graaf 1979_ [doi](https://doi.org/10.1016/0378-4363%2879%2990072-x) | Table 1, p. 2, row 16; `ORC-TSPOWJ3TSF.aa2c44` |  |
| Lattice a | 6.386 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Iandelli 1965_ [doi](https://doi.org/10.1016/0022-5088%2865%2990028-7) | Table 1, p. 2, row 14; `ORC-U4POOWXSEY.d96977` |  |
| Lattice a | 10.416 Å |  | Mg4Eu; _alloy: Mg 0.8_ | DFT | [1] Tao 2008; _cites Zandbergen 1989_ [doi](https://doi.org/10.1016/0022-5088%2889%2990222-1) | Table 1, p. 2, row 11; `ORC-RXRIS7KOZD.5404d1` |  |
| Lattice a | 10.4126 Å |  | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008; _cites Muhlpfordt 1970_ [doi](https://doi.org/10.1002/zaac.19703740206) | Table 1, p. 2, row 10; `ORC-6DBKR4YDMS.19284b` |  |
| Lattice a | 10.3597 Å | 0 | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 9; `ORC-7IC2KCC25R.34c3d8` |  |
| Lattice a | 10.3953 Å |  | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008; _cites Erassme 1987_ [doi](https://doi.org/10.1107/s0108768187097933) | Table 1, p. 2, row 8; `ORC-TRXZ5M5K4R.3a6315` |  |
| Lattice a | 4.0493 Å | 0 | MgEu; _alloy: Mg 0.5_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 17; `ORC-NAJ7DMZ44Q` |  |
| Lattice a | 4.102 Å |  | MgEu; _alloy: Mg 0.5_ | DFT | [1] Tao 2008; _cites Klemm 1964_ [doi](https://doi.org/10.1002/anie.196407043) | Table 1, p. 2, row 18; `ORC-P56I26SXSZ` |  |
| Lattice c | 10.2629 Å | 0 | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 4; `ORC-5XDXT7ZE7V.003ee6` |  |
| Lattice c | 10.33 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Klemm 1964_ [doi](https://doi.org/10.1002/anie.196407043) | Table 1, p. 2, row 5; `ORC-ADGSFIYHCV.ecca78` |  |
| Lattice c | 10.327 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Lueken 1985_ [doi](https://doi.org/10.1016/0022-5088%2885%2990174-2) | Table 1, p. 2, row 7; `ORC-KD4PWPC5UA.744935` |  |
| Lattice c | 10.374 Å |  | Mg17Eu2; _alloy: Mg 0.894737_ | DFT | [1] Tao 2008; _cites Kripyakevich 1969_ | Table 1, p. 2, row 6; `ORC-WBIRBMGIYD.74d993` |  |
| Lattice c | 10.308 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Klemm 1964_ [doi](https://doi.org/10.1002/anie.196407043) | Table 1, p. 2, row 13; `ORC-KXWUZVDCT3.98893a` |  |
| Lattice c | 10.2585 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Buschow 1978_ [doi](https://doi.org/10.1063/1.324939) | Table 1, p. 2, row 15; `ORC-R3MIFFSMZD.5ddb6e` |  |
| Lattice c | 10.2282 Å | 0 | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 12; `ORC-RFZH5N5ZUE.a8ffd3` |  |
| Lattice c | 10.258 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Graaf 1979_ [doi](https://doi.org/10.1016/0378-4363%2879%2990072-x) | Table 1, p. 2, row 16; `ORC-TSPOWJ3TSF.804cf2` |  |
| Lattice c | 10.324 Å |  | Mg2Eu; _alloy: Mg 0.666667_ | DFT | [1] Tao 2008; _cites Iandelli 1965_ [doi](https://doi.org/10.1016/0022-5088%2865%2990028-7) | Table 1, p. 2, row 14; `ORC-U4POOWXSEY.8d3eec` |  |
| Lattice c | 28.051 Å |  | Mg4Eu; _alloy: Mg 0.8_ | DFT | [1] Tao 2008; _cites Zandbergen 1989_ [doi](https://doi.org/10.1016/0022-5088%2889%2990222-1) | Table 1, p. 2, row 11; `ORC-RXRIS7KOZD.a6b402` |  |
| Lattice c | 10.7626 Å |  | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008; _cites Muhlpfordt 1970_ [doi](https://doi.org/10.1002/zaac.19703740206) | Table 1, p. 2, row 10; `ORC-6DBKR4YDMS.0409f0` |  |
| Lattice c | 10.6103 Å | 0 | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008 | Table 1, p. 2, row 9; `ORC-7IC2KCC25R.00612d` |  |
| Lattice c | 10.7463 Å |  | Mg5Eu; _alloy: Mg 0.833333_ | DFT | [1] Tao 2008; _cites Erassme 1987_ [doi](https://doi.org/10.1107/s0108768187097933) | Table 1, p. 2, row 8; `ORC-TRXZ5M5K4R.134a9f` |  |

## Sources

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

1. X.M. Tao, H. Wang, W.J. Zhu, H.S. Liu, Y.F. Ouyang, Z.P. Jin, Thermodynamic description of the Mg–Eu binary system, Calphad 32, 462-465 (2008). [doi:10.1016/j.calphad.2008.07.003](https://doi.org/10.1016/j.calphad.2008.07.003)

## 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=\<id>, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).