# Fe–Nb–P system

> Fe–Nb–P system: 41 accepted literature values (invariant reaction 28, crystal structure 13) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

41 accepted literature values from 2 paper(s) (experimental 12, model 29); 0 calculated phase diagram(s).

Data: [JSON](https://data.orchid-project.org/literature/systems/FE-NB-P.json) · [CSV](https://data.orchid-project.org/systems/FE-NB-P.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#FE-NB-P) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/FE-NB-P.html) · [Markdown](https://data.orchid-project.org/systems/FE-NB-P.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 12 |
| model | 29 |

Table: Accepted values by property group

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

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Fe–Nb–P system (28)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 1810.15 | quasi-peritectic: L + τ1 = λ + τ2 | L: Fe 0.388776, Nb 0.485646, P 0.125578; Liq: Fe 0.388776, Nb 0.485646, P 0.125578 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 16; `ORC-YUV4WFY3DK` |  |
| 1776.15 | L + τ2 = λ + τ3 | L: Fe 0.394664, Nb 0.56853, P 0.036805; Liq: Fe 0.394664, Nb 0.56853, P 0.036805 | experimental | [1] Miettinen 2015; _cites Niessen 1983_ [doi](https://doi.org/10.1016/0364-5916%2883%2990030-5) | Table 4, p. 9, row 19; `ORC-55YP774LRD` |  |
| 1762.15 | eutectic: L = bcc + λ + τ3 | L: Fe 0.362711, Nb 0.612137, P 0.025152; Liq: Fe 0.362711, Nb 0.612137, P 0.025152 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 8; `ORC-3AZCFZN3JO` |  |
| 1760.15 | peritectic: L + τ1 + τ2 = τ3 | L: Fe 0.189044, Nb 0.59151, P 0.219446; Liq: Fe 0.189044, Nb 0.59151, P 0.219446 | model | [1] Miettinen 2015 | Table 4, p. 9, row 28; `ORC-DEK6NNNX2K` |  |
| 1744.15 | quasi-peritectic: L + τ1 = λ + τ2 | L: Fe 0.422015, Nb 0.446337, P 0.131648; Liq: Fe 0.422015, Nb 0.446337, P 0.131648 | model | [1] Miettinen 2015 | Table 4, p. 9, row 14; `ORC-LCOO6NEMA5` |  |
| 1739.15 | eutectic: L = λ + τ2 + τ3 | L: Fe 0.382519, Nb 0.499844, P 0.117637; Liq: Fe 0.382519, Nb 0.499844, P 0.117637 | model | [1] Miettinen 2015 | Table 4, p. 9, row 4; `ORC-C3AAPB25JN` |  |
| 1726.15 | quasi-peritectic: L + μ = λ + τ3 | L: Fe 0.403174, Nb 0.51449, P 0.082336; Liq: Fe 0.403174, Nb 0.51449, P 0.082336 | model | [1] Miettinen 2015 | Table 4, p. 9, row 17; `ORC-XQDUBGBEP3` |  |
| 1725.15 | quasi-peritectic: L + NbP = Nb7P4 + τ1 | L: Fe 0.019257, Nb 0.649749, P 0.330995; Liq: Fe 0.019257, Nb 0.649749, P 0.330995 | model | [1] Miettinen 2015 | Table 4, p. 9, row 21; `ORC-VECUTMBUHM` |  |
| 1704.15 | eutectic: L = bcc + μ + τ3 | L: Fe 0.354938, Nb 0.612438, P 0.032625; Liq: Fe 0.354938, Nb 0.612438, P 0.032625 | model | [1] Miettinen 2015 | Table 4, p. 9, row 6; `ORC-5IJFRH2ZBY` |  |
| 1683.15 | quasi-peritectic: L + τ1 = τ3 + Nb7P4 | L: Fe 0.039805, Nb 0.680303, P 0.279892; Liq: Fe 0.039805, Nb 0.680303, P 0.279892 | model | [1] Miettinen 2015 | Table 4, p. 9, row 20; `ORC-YFCIUA7OJN` |  |
| 1656.15 | eutectic: L = bcc + λ + τ3 | L: Fe 0.287935, Nb 0.620597, P 0.091468; Liq: Fe 0.287935, Nb 0.620597, P 0.091468 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 7; `ORC-4SEYZ5EZVH` |  |
| 1655.15 | quasi-peritectic: L + τ1 = λ + τ2 | L: Fe 0.370748, Nb 0.484232, P 0.14502; Liq: Fe 0.370748, Nb 0.484232, P 0.14502 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 15; `ORC-C7B45VJGGD` |  |
| 1646.15 | L + λ = μ + τ3 | L: Fe 0.331451, Nb 0.548084, P 0.120465; Liq: Fe 0.331451, Nb 0.548084, P 0.120465 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 18; `ORC-IS2B5AXLNK` |  |
| 1636.15 | eutectic: L = λ + τ2 + τ3 | L: Fe 0.337405, Nb 0.525604, P 0.136991; Liq: Fe 0.337405, Nb 0.525604, P 0.136991 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 5; `ORC-Z6QMTPV5LV` |  |
| 1600.15 | eutectic: L = bcc + Nb7P4 + τ3 | L: Fe 0.008389, Nb 0.757183, P 0.234429; Liq: Fe 0.008389, Nb 0.757183, P 0.234429 | model | [1] Miettinen 2015 | Table 4, p. 9, row 9; `ORC-RVHV2GC4VQ` |  |
| 1568.15 | eutectic: L = bcc + λ + τ1 | L: Fe 0.83998, Nb 0.093041, P 0.066979; Liq: Fe 0.83998, Nb 0.093041, P 0.066979 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 3; `ORC-CNTAQTBP7C` |  |
| 1565.15 | eutectic: L = bcc + λ + τ1 | L: Fe 0.810032, Nb 0.118265, P 0.071703; Liq: Fe 0.810032, Nb 0.118265, P 0.071703 | model | [1] Miettinen 2015 | Table 4, p. 9, row 1; `ORC-CGWAGQLX67` |  |
| 1556.15 | eutectic: L = bcc + λ + τ1 | L: Fe 0.82368, Nb 0.110442, P 0.065878; Liq: Fe 0.82368, Nb 0.110442, P 0.065878 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 2; `ORC-Z5JTIRROD2` |  |
| 1548.15 | quasi-peritectic: L + Fe2P = FeP + τ1 | L: Fe 0.589411, Nb 0.018117, P 0.392472; Liq: Fe 0.589411, Nb 0.018117, P 0.392472 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 24; `ORC-QI5YKECJBS` |  |
| 1530.15 | eutectic: L = Fe2P + FeP + τ1 | L: Fe 0.554961, Nb 0.023898, P 0.421141; Liq: Fe 0.554961, Nb 0.023898, P 0.421141 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 23; `ORC-D5AT6IYD6L` |  |
| 1478.15 | quasi-peritectic: L + Fe2P = FeP + τ1 | L: Fe 0.504496, Nb 0.060548, P 0.434957; Liq: Fe 0.504496, Nb 0.060548, P 0.434957 | model | [1] Miettinen 2015 | Table 4, p. 9, row 22; `ORC-WB7PU7MYMF` |  |
| 1475.15 | eutectic: L = NbP + FeP + τ1 | L: Fe 0.461121, Nb 0.084692, P 0.454186; Liq: Fe 0.461121, Nb 0.084692, P 0.454186 | model | [1] Miettinen 2015 | Table 4, p. 9, row 10; `ORC-EZKJBS7H2D` |  |
| 1422.15 | L + Fe2P = Fe3P + τ1 | L: Fe 0.782327, Nb 0.002177, P 0.215496; Liq: Fe 0.782327, Nb 0.002177, P 0.215496 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 26; `ORC-XDZAFCBMGK` |  |
| 1421.15 | quasi-peritectic: L + Fe2P = Fe3P + τ1 | L: Fe 0.774167, Nb 0.005443, P 0.22039; Liq: Fe 0.774167, Nb 0.005443, P 0.22039 | model | [1] Miettinen 2015 | Table 4, p. 9, row 25; `ORC-O5NZ7SU6OP` |  |
| 1398.15 | L + Fe2P = Fe3P + τ1 | L: Fe 0.75959, Nb 0.005403, P 0.235007; Liq: Fe 0.75959, Nb 0.005403, P 0.235007 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 27; `ORC-CBVW26NYNR` |  |
| 1322.15 | eutectic: L = bcc + Fe3P + τ1 | L: Fe 0.835894, Nb 0.001675, P 0.162432; Liq: Fe 0.835894, Nb 0.001675, P 0.162432 | model | [1] Miettinen 2015; _cites Tokunaga 2009_ [doi](https://doi.org/10.2355/isijinternational.49.947) | Table 4, p. 9, row 12; `ORC-AJXCTBHSV2` |  |
| 1318.15 | eutectic: L = bcc + Fe3P + τ1 | L: Fe 0.825654, Nb 0.006707, P 0.167639; Liq: Fe 0.825654, Nb 0.006707, P 0.167639 | experimental | [1] Miettinen 2015; _cites Vogel 1962_ [doi](https://doi.org/10.1002/srin.196203320) | Table 4, p. 9, row 13; `ORC-2FRFJCZ5Q6` |  |
| 1316.15 | eutectic: L = bcc + Fe3P + τ1 | L: Fe 0.829692, Nb 0.004468, P 0.165841; Liq: Fe 0.829692, Nb 0.004468, P 0.165841 | model | [1] Miettinen 2015 | Table 4, p. 9, row 11; `ORC-L6MTIHYWUR` |  |

## Other properties

### Crystal structure (13)

Table: Crystal structure, Fe–Nb–P system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 6.13 Å |  | FeNb4P; _alloy: Nb 0.666667, P 0.166667_ | experimental | [2] Tokunaga 2009 | Table 1, p. 4, row 18; `ORC-6EDRTL7K4A.46ab24` |  |
| Lattice a | 6.16 Å |  | FeNb4P; _alloy: Nb 0.666667, P 0.166667_ | model | [2] Tokunaga 2009 | Table 1, p. 4, row 17; `ORC-TU624ULLNW.1b173c` |  |
| Lattice a | 6.139 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | experimental | [2] Tokunaga 2009 | Table 1, p. 4, row 16; `ORC-B4FAOGIBII.d9affb` |  |
| Lattice a | 6.347 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | model | [2] Tokunaga 2009 | Table 1, p. 4, row 15; `ORC-TAKC57Z5R4.33ada5` |  |
| Lattice a | 6.578 Å |  | Nb2P in FeNbP | model | [2] Tokunaga 2009 | Table 1, p. 4, row 4; `ORC-UUP4B45PIZ.2f1e09` |  |
| Lattice b | 3.585 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | experimental | [2] Tokunaga 2009 | Table 1, p. 4, row 16; `ORC-B4FAOGIBII.2d599f` |  |
| Lattice b | 3.706 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | model | [2] Tokunaga 2009 | Table 1, p. 4, row 15; `ORC-TAKC57Z5R4.b0978e` |  |
| Lattice b | 3.941 Å |  | Nb2P in FeNbP | model | [2] Tokunaga 2009 | Table 1, p. 4, row 4; `ORC-UUP4B45PIZ.06eab4` |  |
| Lattice c | 5.006 Å |  | FeNb4P; _alloy: Nb 0.666667, P 0.166667_ | experimental | [2] Tokunaga 2009 | Table 1, p. 4, row 18; `ORC-6EDRTL7K4A.675b70` |  |
| Lattice c | 5.03 Å |  | FeNb4P; _alloy: Nb 0.666667, P 0.166667_ | model | [2] Tokunaga 2009 | Table 1, p. 4, row 17; `ORC-TU624ULLNW.f47870` |  |
| Lattice c | 7.006 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | experimental | [2] Tokunaga 2009 | Table 1, p. 4, row 16; `ORC-B4FAOGIBII.d15be7` |  |
| Lattice c | 7.243 Å |  | FeNbP; _alloy: Nb 0.333333, P 0.333333_ | model | [2] Tokunaga 2009 | Table 1, p. 4, row 15; `ORC-TAKC57Z5R4.187b04` |  |
| Lattice c | 7.552 Å |  | Nb2P in FeNbP | model | [2] Tokunaga 2009 | Table 1, p. 4, row 4; `ORC-UUP4B45PIZ.bb06a0` |  |

## Sources

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

1. Jyrki Miettinen, Gueorgui Vassilev, Thermodynamic Description of Ternary Fe-X-P systems. Part 5: Fe-Nb-P, J. Phase Equilib. Diffus. 36, 68-77 (2015). [doi:10.1007/s11669-014-0351-5](https://doi.org/10.1007/s11669-014-0351-5)
2. Tatsuya Tokunaga, Naoko Hanaya, Hiroshi Ohtani, Mitsuhiro Hasebe, Thermodynamic Analysis of Phase Equilibria in the Fe–Nb–P Ternary System, ISIJ Int. 49, 947-956 (2009). [doi:10.2355/isijinternational.49.947](https://doi.org/10.2355/isijinternational.49.947)

## 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 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_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/).