# Al–Hf system

> Al–Hf system: 55 accepted literature values (invariant reaction 29, formation 26) and 1 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/AL-HF.html · Markdown: https://data.orchid-project.org/systems/AL-HF.md

55 accepted literature values from 1 paper(s) (experimental 19, model 36); 1 calculated phase diagram(s).

Data: [JSON](https://data.orchid-project.org/literature/systems/AL-HF.json) · [CSV](https://data.orchid-project.org/systems/AL-HF.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#AL-HF) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#AL-HF/AlHf-02Wan.json) · [phases (12)](https://data.orchid-project.org/phases/pages/AL-HF.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/AL-HF.html) · [Markdown](https://data.orchid-project.org/systems/AL-HF.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 19 |
| model | 36 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 29 |
| formation | 26 |

## 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 |
|---|---|---|---|
| AlHf-02Wan.tdb | T. Wang, Z. Jin, J.-C. Zhao, J. Phase Equilib., 23, 416-23(2002). [doi:10.1361/105497102770331361](https://doi.org/10.1361/105497102770331361) | `5a64ef43c1f8c593139372013ed422d67782199ea4f2edfa5f0f0c72c3d40394` | [viewer](https://orchid-project.org/phase-diagrams/#AL-HF/AlHf-02Wan.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AlHf-02Wan.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AlHf-02Wan.json) |

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

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| AlHf-02Wan.tdb | 1911.13 | AL3HF2 (x(Hf) 0.4) + LIQUID (x(Hf) 0.42681) + ALHF_B33 (x(Hf) 0.5) |
| AlHf-02Wan.tdb | 1911.13 | AL3HF2 (x(Hf) 0.4) + LIQUID (x(Hf) 0.42696) + ALHF_B33 (x(Hf) 0.5) |
| AlHf-02Wan.tdb | 1878.71 | AL2HF_C14 (x(Hf) 0.33333) + LIQUID (x(Hf) 0.35303) + AL3HF2 (x(Hf) 0.4) |
| AlHf-02Wan.tdb | 1878.71 | AL2HF_C14 (x(Hf) 0.33333) + LIQUID (x(Hf) 0.35329) + AL3HF2 (x(Hf) 0.4) |
| AlHf-02Wan.tdb | 1841.57 | AL3HF_D022 (x(Hf) 0.25) + LIQUID (x(Hf) 0.28281) + AL2HF_C14 (x(Hf) 0.33333) |
| AlHf-02Wan.tdb | 1841.57 | AL3HF_D022 (x(Hf) 0.25) + LIQUID (x(Hf) 0.2826) + AL2HF_C14 (x(Hf) 0.33333) |
| AlHf-02Wan.tdb | 1838.59 | ALHF_B33 (x(Hf) 0.5) + LIQUID (x(Hf) 0.58993) + AL2HF3 (x(Hf) 0.6) |
| AlHf-02Wan.tdb | 1838.58 | ALHF_B33 (x(Hf) 0.5) + LIQUID (x(Hf) 0.59021) + AL2HF3 (x(Hf) 0.6) |
| AlHf-02Wan.tdb | 1800.53 | AL2HF3 (x(Hf) 0.6) + LIQUID (x(Hf) 0.65251) + BCC_A2 (x(Hf) 0.68997) |
| AlHf-02Wan.tdb | 1800.53 | AL2HF3 (x(Hf) 0.6) + LIQUID (x(Hf) 0.65257) + BCC_A2 (x(Hf) 0.69003) |
| AlHf-02Wan.tdb | 1726.93 | AL2HF3 (x(Hf) 0.6) + BCC_A2 (x(Hf) 0.71882) + HCP_A3 (x(Hf) 0.72776) |
| AlHf-02Wan.tdb | 1726.93 | AL2HF3 (x(Hf) 0.6) + BCC_A2 (x(Hf) 0.71897) + HCP_A3 (x(Hf) 0.72791) |
| AlHf-02Wan.tdb | 1673.17 | ALHF_B33 (x(Hf) 0.5) + AL3HF4 (x(Hf) 0.57143) + AL2HF3 (x(Hf) 0.6) |
| AlHf-02Wan.tdb | 1473.27 | AL2HF3 (x(Hf) 0.6) + ALHF2_C16 (x(Hf) 0.66667) + HCP_A3 (x(Hf) 0.802) |
| AlHf-02Wan.tdb | 1473.27 | AL2HF3 (x(Hf) 0.6) + ALHF2_C16 (x(Hf) 0.66667) + HCP_A3 (x(Hf) 0.80209) |
| AlHf-02Wan.tdb | 1473.27 | AL2HF3 (x(Hf) 0.6) + ALHF2_C16 (x(Hf) 0.66667) + HCP_A3 (x(Hf) 0.80207) |
| AlHf-02Wan.tdb | 1473.27 | AL2HF3 (x(Hf) 0.6) + ALHF2_C16 (x(Hf) 0.66667) + HCP_A3 (x(Hf) 0.8021) |
| AlHf-02Wan.tdb | 934.73 | LIQUID (x(Hf) 6.200e-4) + FCC_A1 (x(Hf) 0.00243) + AL3HF_D022 (x(Hf) 0.25) |
| AlHf-02Wan.tdb | 934.73 | LIQUID (x(Hf) 6.000e-4) + FCC_A1 (x(Hf) 0.00237) + AL3HF_D022 (x(Hf) 0.25) |
| AlHf-02Wan.tdb | 923.08 | FCC_A1 (x(Hf) 0.00219) + AL3HF_D023 (x(Hf) 0.25) + AL3HF_D022 (x(Hf) 0.25) |
| AlHf-02Wan.tdb | 923.08 | AL3HF_D022 (x(Hf) 0.25) + AL3HF_D023 (x(Hf) 0.25) + AL2HF_C14 (x(Hf) 0.33333) |
| AlHf-02Wan.tdb | 923.08 | FCC_A1 (x(Hf) 0.00219) + AL3HF_D023 (x(Hf) 0.25) + AL3HF_D022 (x(Hf) 0.25) |
| AlHf-02Wan.tdb | 923.08 | FCC_A1 (x(Hf) 0.00219) + AL3HF_D022 (x(Hf) 0.25) + AL3HF_D023 (x(Hf) 0.25) |

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

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Al–Hf system (29)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 2073 | congruent melting: L ↔ HfAl | HfAl: Al 0.5 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 13; `ORC-47RNLAS5G4` |  |
| 2034 | congruent melting: L ↔ HfAl | HfAl: Al 0.5 | model | [1] Wang 2002 | Table 1, p. 2, row 14; `ORC-BTH4OI6UT6` |  |
| 1929 | congruent melting: L ↔ Hf2Al3 | Hf2Al3: Al 0.6 | model | [1] Wang 2002 | Table 1, p. 2, row 17; `ORC-HWTYPWVXR5` |  |
| 1923 | congruent melting: L ↔ HFAl2 | HFAl2: Al 0.667 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 20; `ORC-KENSBUKCD5` |  |
| 1913 | L + HfAl ↔ Hf2Al3 | HfAl: Al 0.5; Hf2Al3: Al 0.6 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 15; `ORC-A6URKQSQ4W` |  |
| 1911 | L ↔ HfAl + Hf2Al3 | L: Al 0.573; HfAl: Al 0.5; Hf2Al3: Al 0.6 | model | [1] Wang 2002 | Table 1, p. 2, row 16; `ORC-AMLFD5IARL` |  |
| 1886 | congruent melting: L ↔ HFAl2 | HFAl2: Al 0.667 | model | [1] Wang 2002 | Table 1, p. 2, row 21; `ORC-EK7GYBD5J7` |  |
| 1879 | L ↔ Hf2Al3 + HfAl2 | L: Al 0.647; Hf2Al3: Al 0.6; HfAl2: Al 0.667 | model | [1] Wang 2002 | Table 1, p. 2, row 19; `ORC-3PD74KBM6X` |  |
| 1863 | congruent melting: L ↔ HfAl3(β) | HfAl3(β): Al 0.75 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 24; `ORC-SF45U7TBUG` |  |
| 1863 | congruent melting: L ↔ Hf3Al2 | Hf3Al2: Al 0.4 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 7; `ORC-T55YIL4B35` |  |
| 1856 | congruent melting: L ↔ HfAl3(β) | HfAl3(β): Al 0.75 | model | [1] Wang 2002 | Table 1, p. 2, row 25; `ORC-U2RZEWB3KO` |  |
| 1842 | L ↔ HfAl2 + HfAl3(β) | L: Al 0.717; HfAl2: Al 0.667; HfAl3(β): Al 0.75 | model | [1] Wang 2002 | Table 1, p. 2, row 23; `ORC-TG6R6ZXIPP` |  |
| 1840 | congruent melting: L ↔ Hf3Al2 | Hf3Al2: Al 0.4 | model | [1] Wang 2002 | Table 1, p. 2, row 8; `ORC-P3ZQFCBBQU` |  |
| 1839 | L ↔ Hf3Al2 + HfAl | L: Al 0.41; Hf3Al2: Al 0.4; HfAl: Al 0.5 | model | [1] Wang 2002 | Table 1, p. 2, row 10; `ORC-D7MGVDHTPO` |  |
| 1823 | L ↔ Hf3Al2 + HfAl | L: Al 0.45; Hf3Al2: Al 0.4; HfAl: Al 0.5 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 9; `ORC-AOFSJARR7K` |  |
| 1813 | L ↔ HfAl2 + HfAl3(β) | HfAl2: Al 0.667; HfAl3(β): Al 0.75 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 22; `ORC-BPSTWTSNOM` |  |
| 1803 | L ↔ bcc + Hf3Al2 | L: Al 0.36; bcc: Al 0.33; Hf3Al2: Al 0.4 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 5; `ORC-R46FMEZ6Q3` |  |
| 1801 | L ↔ bcc + Hf3Al2 | L: Al 0.347; bcc: Al 0.31; Hf3Al2: Al 0.4 | model | [1] Wang 2002 | Table 1, p. 2, row 6; `ORC-DE66T45K6P` |  |
| 1768 | L ↔ Hf2Al3 + HfAl2 | Hf2Al3: Al 0.6; HfAl2: Al 0.667 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 18; `ORC-JA4BVLOAHA` |  |
| 1727 | bcc ↔ cph + Hf3Al2 | bcc: Al 0.281; cph: Al 0.272; Hf3Al2: Al 0.4 | model | [1] Wang 2002 | Table 1, p. 2, row 2; `ORC-3KZWV3SQGL` |  |
| 1723 | bcc ↔ cph + Hf3Al2 | bcc: Al 0.3; cph: Al 0.27; Hf3Al2: Al 0.4 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 1; `ORC-3BG5BGJM7V` |  |
| 1673 | Hf3Al2 + HfAl ↔ Hf4Al3 | Hf3Al2: Al 0.4; HfAl: Al 0.5; Hf4Al3: Al 0.429 | model | [1] Wang 2002 | Table 1, p. 2, row 12; `ORC-NXXZ6BXUMU` |  |
| 1473 | cph + Hf3Al2 ↔ Hf2Al | cph: Al 0.198; Hf3Al2: Al 0.4; Hf2Al: Al 0.333 | model | [1] Wang 2002 | Table 1, p. 2, row 4; `ORC-XCTRQPU77R` |  |
| 1273 | cph + Hf3Al2 ↔ Hf2Al | Hf3Al2: Al 0.4, Hf 0.6; Hf2Al: Al 0.333333, Hf 0.666667 | experimental | [1] Wang 2002; _cites Tsyganova 1970_ | Table 1, p. 2, row 3; `ORC-RU5XPTOJZ7` |  |
| 1223 | Hf3Al2 + HfAl ↔ Hf4Al3 | Hf3Al2: Al 0.4; HfAl: Al 0.5; Hf4Al3: Al 0.429 | experimental | [1] Wang 2002; _cites Potzschke 1962_ | Table 1, p. 2, row 11; `ORC-LPJLJLT7HH` |  |
| 935.3 | HfAl3(β) + L ↔ fcc | HfAl3(β): Al 0.75; L: Al 0.9993; fcc: Al 0.9981 | experimental | [1] Wang 2002; _cites Rath 1960_ | Table 1, p. 2, row 26; `ORC-3AZUPB32YE` |  |
| 934.8 | HfAl3(β) + L ↔ fcc | HfAl3(β): Al 0.75; L: Al 0.9994; fcc: Al 0.9976 | model | [1] Wang 2002 | Table 1, p. 2, row 27; `ORC-3D2F3MYNMD` |  |
| 923 | polymorphic: HfAl3(β) ↔ HfAl3(α) | HfAl3(β): Al 0.75 | experimental | [1] Wang 2002; _cites Potzschke 1962_ | Table 1, p. 2, row 28; `ORC-DUHBMTCHIV` |  |
| 923 | polymorphic: HfAl3(β) ↔ HfAl3(α) | HfAl3(β): Al 0.75 | model | [1] Wang 2002 | Table 1, p. 2, row 29; `ORC-JG5MPF5F6F` |  |

## 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, Al–Hf system (26)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Hf2Al | [AlHf2](https://data.orchid-project.org/compounds/AlHf2.html) | -41.2 kJ/mol-atom |  | model | -25.526 (mp-aaaaasxg) | -25.508 (oqmd-19400) | [1] Wang 2002 | Table 2, p. 3, row 3; `ORC-272IXOMJZP` |  |
| Hf2Al | [AlHf2](https://data.orchid-project.org/compounds/AlHf2.html) | -41 kJ/mol-atom |  | model | -25.526 (mp-aaaaasxg) | -25.508 (oqmd-19400) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 1; `ORC-H7ATN5M4J6` |  |
| Hf2Al | [AlHf2](https://data.orchid-project.org/compounds/AlHf2.html) | -38.9 kJ/mol-atom |  | model | -25.526 (mp-aaaaasxg) | -25.508 (oqmd-19400) | [1] Wang 2002 | Table 2, p. 3, row 2; `ORC-2MDQVL4PQG` |  |
| Hf2Al3 | [Al3Hf2](https://data.orchid-project.org/compounds/Al3Hf2.html) | -49.2 kJ/mol-atom |  | model | -41.152 (mp-aaaaabgo) | -41.101 (oqmd-19010) | [1] Wang 2002 | Table 2, p. 3, row 16; `ORC-GU3IQQP2JB` |  |
| Hf2Al3 | [Al3Hf2](https://data.orchid-project.org/compounds/Al3Hf2.html) | -47.5 kJ/mol-atom |  | model | -41.152 (mp-aaaaabgo) | -41.101 (oqmd-19010) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 15; `ORC-A6GWJYJZ62` |  |
| Hf2Al3 | [Al3Hf2](https://data.orchid-project.org/compounds/Al3Hf2.html) | -42.9 kJ/mol-atom |  | model | -41.152 (mp-aaaaabgo) | -41.101 (oqmd-19010) | [1] Wang 2002 | Table 2, p. 3, row 17; `ORC-XYIUW3AAEV` |  |
| Hf2Al3 | [Al3Hf2](https://data.orchid-project.org/compounds/Al3Hf2.html) | -40.8 kJ/mol-atom | 298.15 | experimental | -41.152 (mp-aaaaabgo) | -41.101 (oqmd-19010) | [1] Wang 2002; _cites Balducci 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2906039-8) | Table 2, p. 3, row 14; `ORC-KBQOXUGQIW` |  |
| Hf3Al2 | [Al2Hf3](https://data.orchid-project.org/compounds/Al2Hf3.html) | -48.9 kJ/mol-atom |  | model | -31.894 (mp-aaaaamnm) | -31.931 (oqmd-11338) | [1] Wang 2002 | Table 2, p. 3, row 6; `ORC-IYHU6Z5SN3` |  |
| Hf3Al2 | [Al2Hf3](https://data.orchid-project.org/compounds/Al2Hf3.html) | -45 kJ/mol-atom |  | model | -31.894 (mp-aaaaamnm) | -31.931 (oqmd-11338) | [1] Wang 2002 | Table 2, p. 3, row 5; `ORC-OCUDZAIO53` |  |
| Hf3Al2 | [Al2Hf3](https://data.orchid-project.org/compounds/Al2Hf3.html) | -43.5 kJ/mol-atom |  | model | -31.894 (mp-aaaaamnm) | -31.931 (oqmd-11338) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 4; `ORC-TXWBMFUIM2` |  |
| Hf4Al3 | [Al3Hf4](https://data.orchid-project.org/compounds/Al3Hf4.html) | -47.9 kJ/mol-atom |  | model | -38 (mp-aaacgipr) | -37.785 (oqmd-27836) | [1] Wang 2002 | Table 2, p. 3, row 9; `ORC-VDEYROWCAP` |  |
| Hf4Al3 | [Al3Hf4](https://data.orchid-project.org/compounds/Al3Hf4.html) | -47.1 kJ/mol-atom |  | model | -38 (mp-aaacgipr) | -37.785 (oqmd-27836) | [1] Wang 2002 | Table 2, p. 3, row 8; `ORC-ORBJUA7PMB` |  |
| Hf4Al3 | [Al3Hf4](https://data.orchid-project.org/compounds/Al3Hf4.html) | -44.4 kJ/mol-atom |  | model | -38 (mp-aaacgipr) | -37.785 (oqmd-27836) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 7; `ORC-QJBSIFLPT2` |  |
| HfAl | [AlHf](https://data.orchid-project.org/compounds/AlHf.html) | -50.3 kJ/mol-atom |  | model | -38.759 (mp-aaaaaajp) | -38.774 (oqmd-18706) | [1] Wang 2002 | Table 2, p. 3, row 12; `ORC-3XM7NEEBUB` |  |
| HfAl | [AlHf](https://data.orchid-project.org/compounds/AlHf.html) | -46.3 kJ/mol-atom |  | model | -38.759 (mp-aaaaaajp) | -38.774 (oqmd-18706) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 11; `ORC-LKFGJNOSKA` |  |
| HfAl | [AlHf](https://data.orchid-project.org/compounds/AlHf.html) | -45.2 kJ/mol-atom |  | model | -38.759 (mp-aaaaaajp) | -38.774 (oqmd-18706) | [1] Wang 2002 | Table 2, p. 3, row 13; `ORC-CO3ZHQ5MU5` |  |
| HfAl | [AlHf](https://data.orchid-project.org/compounds/AlHf.html) | -39.9 kJ/mol-atom | 298.15 | experimental | -38.759 (mp-aaaaaajp) | -38.774 (oqmd-18706) | [1] Wang 2002; _cites Meschel 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990621-s) | Table 2, p. 3, row 10; `ORC-O3DEJUQXKL` |  |
| HfAl2 | [Al2Hf](https://data.orchid-project.org/compounds/Al2Hf.html) | -48.3 kJ/mol-atom |  | model | -42.633 (mp-aaaaassv) | -42.842 (oqmd-19094) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 19; `ORC-WSAYULNCVA` |  |
| HfAl2 | [Al2Hf](https://data.orchid-project.org/compounds/Al2Hf.html) | -44.7 kJ/mol-atom |  | model | -42.633 (mp-aaaaassv) | -42.842 (oqmd-19094) | [1] Wang 2002 | Table 2, p. 3, row 20; `ORC-77G3WVIKLZ` |  |
| HfAl2 | [Al2Hf](https://data.orchid-project.org/compounds/Al2Hf.html) | -43.8 kJ/mol-atom | 298.15 | experimental | -42.633 (mp-aaaaassv) | -42.842 (oqmd-19094) | [1] Wang 2002; _cites Meschel 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990621-s) | Table 2, p. 3, row 18; `ORC-DWELRRJ7TF` |  |
| HfAl2 | [Al2Hf](https://data.orchid-project.org/compounds/Al2Hf.html) | -41.7 kJ/mol-atom |  | model | -42.633 (mp-aaaaassv) | -42.842 (oqmd-19094) | [1] Wang 2002 | Table 2, p. 3, row 21; `ORC-ISQR3YV3ZG` |  |
| HfAl3 | [Al3Hf](https://data.orchid-project.org/compounds/Al3Hf.html) | -44.7 kJ/mol-atom | 298.15 | experimental | -38.14 (mp-aaabgjhu) | -38.236 (oqmd-19074) | [1] Wang 2002; _cites Balducci 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2906039-8) | Table 2, p. 3, row 23; `ORC-H3GLAFRIM7` |  |
| HfAl3 | [Al3Hf](https://data.orchid-project.org/compounds/Al3Hf.html) | -41.8 kJ/mol-atom |  | model | -38.14 (mp-aaabgjhu) | -38.236 (oqmd-19074) | [1] Wang 2002; _cites ref. 1975Kao_ | Table 2, p. 3, row 24; `ORC-DDFGOZ3PKZ` |  |
| HfAl3 | [Al3Hf](https://data.orchid-project.org/compounds/Al3Hf.html) | -41.1 kJ/mol-atom |  | model | -38.14 (mp-aaabgjhu) | -38.236 (oqmd-19074) | [1] Wang 2002 | Table 2, p. 3, row 26; `ORC-AL35XEQFMA` |  |
| HfAl3 | [Al3Hf](https://data.orchid-project.org/compounds/Al3Hf.html) | -40.6 kJ/mol-atom | 298.15 | experimental | -38.14 (mp-aaabgjhu) | -38.236 (oqmd-19074) | [1] Wang 2002; _cites Meschel 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990621-s) | Table 2, p. 3, row 22; `ORC-UVWYIQWC3J` |  |
| HfAl3 | [Al3Hf](https://data.orchid-project.org/compounds/Al3Hf.html) | -35.6 kJ/mol-atom |  | model | -38.14 (mp-aaabgjhu) | -38.236 (oqmd-19074) | [1] Wang 2002 | Table 2, p. 3, row 25; `ORC-6JLUSDS27Q` |  |

## Sources

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

1. Tao Wang, Zhanpeng Jin, Ji-Cheng Zhao, Thermodynamic assessment of the Al-Hf binary system, JPE 23, 416-423 (2002). [doi:10.1361/105497102770331361](https://doi.org/10.1361/105497102770331361)

## 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/).