# Cu–Ir system

> Cu–Ir system: 33 accepted literature values (phase equilibrium 24, crystal structure 8, activity / EMF / Gibbs energy 1) and 2 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/CU-IR.html · Markdown: https://data.orchid-project.org/systems/CU-IR.md

33 accepted literature values from 1 paper(s) (experimental 8, model 15, unspecified 10); 2 calculated phase diagram(s). 3 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/CU-IR.json) · [CSV](https://data.orchid-project.org/systems/CU-IR.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#CU-IR) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#CU-IR/CuIr-04Kor-LB.json) · [phases (4)](https://data.orchid-project.org/phases/pages/CU-IR.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/CU-IR.html) · [Markdown](https://data.orchid-project.org/systems/CU-IR.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 8 |
| model | 15 |
| unspecified | 10 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| phase equilibrium | 24 |
| activity / EMF / Gibbs energy | 1 |
| crystal structure | 8 |

## 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 |
|---|---|---|---|
| CuIr-04Kor-LB.tdb | J. Korb, unpublished work, GTT, 2004. | `bc7d8e92a01c7ed06d721d920a89d9758432138326a7b50dbffdc4a44fe9349b` | [viewer](https://orchid-project.org/phase-diagrams/#CU-IR/CuIr-04Kor-LB.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CuIr-04Kor-LB.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CuIr-04Kor-LB.json) |
| CuIr-87Cha.tdb | D.J. Chakrabarti, D.E. Laughlin, Bull. Alloy Phase Diag., 8, 132-36(1987). [doi:10.1007/BF02873198](https://doi.org/10.1007/BF02873198) | `f9fe888f4dc6f8ff7058c3ba7c9f7aaa7ee7b95ed9ffe8a038f8636604b1769b` | [viewer](https://orchid-project.org/phase-diagrams/#CU-IR/CuIr-87Cha.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CuIr-87Cha.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CuIr-87Cha.json) |

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

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| CuIr-04Kor-LB.tdb | 1418.24 | LIQUID (x(Ir) 0.04212) + FCC_A1#2 (x(Ir) 0.10024) + FCC_A1 (x(Ir) 0.96687) |
| CuIr-87Cha.tdb | 1403.89 | LIQUID (x(Ir) 0.03221) + FCC_A1#2 (x(Ir) 0.0786) + FCC_A1 (x(Ir) 0.97024) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/CU/CU-IR.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/CU/CU-IR.json) · [CALPHAD hull CuIr-87Cha](https://data.orchid-project.org/hulls/calphad-sgte/CU/CU-IR--CuIr-87Cha.json)

## Other properties

### Phase equilibrium (24)

Table: Phase equilibrium, Cu–Ir system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase composition |  | 773.15 | (Cu) + (Ir); _(Cu): Cu 0.994, Ir 0.006; (Ir): Cu 0.001, Ir 0.999_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 24; `ORC-OUDOQBTBHC` |  |
| Phase composition |  | 973.15 | (Cu); _(Cu): Cu 0.969, Ir 0.031_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 10; `ORC-4HWVLUMAXZ` |  |
| Phase composition |  | 973.15 | (Cu) + (Ir); _(Cu): Cu 0.981, Ir 0.019; (Ir): Cu 0.005, Ir 0.995_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 23; `ORC-ZPWPUKQCNR` |  |
| Phase composition |  | 1073.15 | (Cu) + (Ir); _(Cu): Cu 0.972, Ir 0.028; (Ir): Cu 0.008, Ir 0.992_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 22; `ORC-5ZPVA2YKPA` |  |
| Phase composition |  | 1073.15 | (Ir); _(Ir): Cu 0.014, Ir 0.986_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 9; `ORC-J27BTO2SVV` |  |
| Phase composition |  | 1133.15 | (Cu); _(Cu): Cu 0.945, Ir 0.055_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 8; `ORC-VZ5DADP3MH` |  |
| Phase composition |  | 1173.15 | (Cu) + (Ir); _(Cu): Cu 0.959, Ir 0.041; (Ir): Cu 0.013, Ir 0.987_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 21; `ORC-3MZ2M76GOQ` |  |
| Phase composition |  | 1293.15 | (Cu); _(Cu): Cu 0.935, Ir 0.065_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 7; `ORC-Z6BGS3A4JO` |  |
| Phase composition |  | 1358.02 | Liquidus + Solidus + L + (Cu); _Liquidus: Cu 1, Ir 0; Solidus: Cu 1, Ir 0; L: Cu 1, Ir 0; (Cu): Cu 1, Ir 0_ | unspecified | [1] Chakrabarti 1987 | Table 1, p. 2, row 2; `ORC-PMXKHU53ZR` |  |
| Phase composition |  | 1363.15 | (Ir); _(Ir): Cu 0.03, Ir 0.97_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 6; `ORC-7IJSBCIG6I` |  |
| Phase composition |  | 1373.15 | (Cu) + (Ir); _(Cu): Cu 0.927, Ir 0.073; (Ir): Cu 0.027, Ir 0.973_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 20; `ORC-ZQ46XDCVMN` |  |
| Phase composition |  | 1411.15 | (Cu) + (Ir); _(Cu): Cu 0.92, Ir 0.08; (Ir): Cu 0.03, Ir 0.97_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 19; `ORC-WPQXXOXYV3` |  |
| Phase composition |  | 1411.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.96, Ir 0.04; Solidus: Cu 0.03, Ir 0.97; L: Cu 0.96, Ir 0.04; (Ir): Cu 0.03, Ir 0.97_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 18; `ORC-HIZM2WFJKD` |  |
| Phase composition |  | 1473.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.95, Ir 0.05; Solidus: Cu 0.034, Ir 0.966; L: Cu 0.95, Ir 0.05; (Ir): Cu 0.034, Ir 0.966_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 17; `ORC-ZNB72WTJHN` |  |
| Phase composition |  | 1473.15 | Solidus + (Ir); _Solidus: Cu 0.032, Ir 0.968; (Ir): Cu 0.032, Ir 0.968_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 5; `ORC-XNKQF4LQY4` |  |
| Phase composition |  | 1673.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.905, Ir 0.095; Solidus: Cu 0.046, Ir 0.954; L: Cu 0.905, Ir 0.095; (Ir): Cu 0.046, Ir 0.954_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 16; `ORC-OLXHF46SYF` |  |
| Phase composition |  | 1673.15 | Solidus + (Ir); _Solidus: Cu 0.051, Ir 0.949; (Ir): Cu 0.051, Ir 0.949_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 4; `ORC-Q5OFOI4XUS` |  |
| Phase composition |  | 1873.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.827, Ir 0.173; Solidus: Cu 0.057, Ir 0.943; L: Cu 0.827, Ir 0.173; (Ir): Cu 0.057, Ir 0.943_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 15; `ORC-P45PTYU3UA` |  |
| Phase composition |  | 1873.15 | Solidus + (Ir); _Solidus: Cu 0.073, Ir 0.927; (Ir): Cu 0.073, Ir 0.927_ | experimental | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 1, p. 2, row 3; `ORC-NB7BELGORK` |  |
| Phase composition |  | 2073.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.678, Ir 0.322; Solidus: Cu 0.063, Ir 0.937; L: Cu 0.678, Ir 0.322; (Ir): Cu 0.063, Ir 0.937_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 14; `ORC-OMCFLHGZMD` |  |
| Phase composition |  | 2273.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.39, Ir 0.61; Solidus: Cu 0.057, Ir 0.943; L: Cu 0.39, Ir 0.61; (Ir): Cu 0.057, Ir 0.943_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 13; `ORC-WKPTUPCXD5` |  |
| Phase composition |  | 2473.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.171, Ir 0.829; Solidus: Cu 0.037, Ir 0.963; L: Cu 0.171, Ir 0.829; (Ir): Cu 0.037, Ir 0.963_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 12; `ORC-NDNKH35CV3` |  |
| Phase composition |  | 2673.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0.028, Ir 0.972; Solidus: Cu 0.007, Ir 0.993; L: Cu 0.028, Ir 0.972; (Ir): Cu 0.007, Ir 0.993_ | model | [1] Chakrabarti 1987 | Table 1, p. 2, row 11; `ORC-ZMRVSRET6N` |  |
| Phase composition |  | 2720.15 | Liquidus + Solidus + L + (Ir); _Liquidus: Cu 0, Ir 1; Solidus: Cu 0, Ir 1; L: Cu 0, Ir 1; (Ir): Cu 0, Ir 1_ | unspecified | [1] Chakrabarti 1987 | Table 1, p. 2, row 1; `ORC-DHCC2ZAHFH` |  |

### Activity / EMF / Gibbs energy (1)

Table: Activity / EMF / Gibbs energy, Cu–Ir system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy; _printed: G (L)_ | -0.59 kJ/mol | 1273.15 |  | model | [1] Chakrabarti 1987 | p. 4; `ORC-D7L4OHIBUO` | “The corresponding integral molar Gibbs energy G (L) (based on pure liquid Cu and pure liquid Ir as standard states), estimated at 1000 ~ is -0.59 kJ/mol.” |

### Crystal structure (8)

Table: Crystal structure, Cu–Ir system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 3.836 Å | 1073.15 | (Ir); _alloy: Cu 0.6, Ir 0.4_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 7; `ORC-NIPMWOLYZL` |  |
| Lattice a | 3.623 Å | 1133.15 | (Cu); _alloy: Cu 0.97, Ir 0.03_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 3; `ORC-DSPUPU2MKL` |  |
| Lattice a | 3.625 Å | 1133.15 | (Cu); _alloy: Cu 0.96, Ir 0.04_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 4; `ORC-HZCX7NTWJW` |  |
| Lattice a | 3.629 Å | 1133.15 | (Cu); _alloy: Cu 0.95, Ir 0.05_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 5; `ORC-JQB4AARVXP` |  |
| Lattice a | 3.621 Å | 1133.15 | (Cu); _alloy: Cu 0.98, Ir 0.02_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 2; `ORC-VEDWTCD66G` |  |
| Lattice a | 3.832 Å | 1473.15 | (Ir); _alloy: Cu 0.4, Ir 0.6_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 8; `ORC-MVRDNDZNXN` |  |
| Lattice a | 3.828 Å | 1673.15 | (Ir); _alloy: Cu 0.4, Ir 0.6_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 9; `ORC-SCFDWEJTWO` |  |
| Lattice a | 3.823 Å | 1873.15 | (Ir); _alloy: Cu 0.4, Ir 0.6_ | unspecified | [1] Chakrabarti 1987; _cites ref. 69Rau_ | Table 3, p. 3, row 10; `ORC-CE2KKKHIOL` |  |

## Sources

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

1. D. J. Chakrabarti, D. E. Laughlin, The Cu−Ir (Copper-Iridium) system, JPE 8, 132-136 (1987). [doi:10.1007/bf02873198](https://doi.org/10.1007/bf02873198)

## 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/).