# Al–Ta system

> Al–Ta system: 225 accepted literature values (phase transition 67, crystal structure 52, invariant reaction 50, phase equilibrium 24) and 4 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

225 accepted literature values from 4 paper(s) (experimental 141, model 55, DFT 1, unspecified 28); 4 calculated phase diagram(s). 13 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/AL-TA.json) · [CSV](https://data.orchid-project.org/systems/AL-TA.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#AL-TA) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#AL-TA/AlTa-10Wit.json) · [phases (14)](https://data.orchid-project.org/phases/pages/AL-TA.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/AL-TA.html) · [Markdown](https://data.orchid-project.org/systems/AL-TA.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 141 |
| model | 55 |
| DFT | 1 |
| unspecified | 28 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 50 |
| phase transition | 67 |
| phase equilibrium | 24 |
| formation | 10 |
| heat capacity / entropy / enthalpy | 12 |
| activity / EMF / Gibbs energy | 10 |
| crystal structure | 52 |

## 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 |
|---|---|---|---|
| AlTa-10Wit.tdb | V.T. Witusiewicz, A.A. Bondar, U. Hecht, J. Zollinger, V.M. Petyukh, O.S. Fomichov, V.M. Voblikov, S. Rex, Intermetallics, 18, 92-106(2010). [doi:10.1016/j.intermet.2009.06.015](https://doi.org/10.1016/j.intermet.2009.06.015) | `667ded9a7ea8878f3222ee4f662340df13cf6f2d940a83ab8f5c516a9de1d21d` | [viewer](https://orchid-project.org/phase-diagrams/#AL-TA/AlTa-10Wit.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AlTa-10Wit.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AlTa-10Wit.json) |
| AlTa-90Kat.tdb | U. Kattner, unpublished, 1990 | `a4157073c1d594d6499968e97e6578f1f11ff260a11bd747040e7150e2af7755` | [viewer](https://orchid-project.org/phase-diagrams/#AL-TA/AlTa-90Kat.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AlTa-90Kat.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AlTa-90Kat.json) |
| AlTa-96Du-LB.tdb | Y. Du, R. Schmid-Fetzer, J. Phase Equilib., 17, 311-324(1996). [doi:10.1007/BF02665557](https://doi.org/10.1007/BF02665557) | `db1782b402270c1409f3fd8e43bd1f2098c4ec9f6a46ef979dc7ac7b3378fdd9` | [viewer](https://orchid-project.org/phase-diagrams/#AL-TA/AlTa-96Du-LB.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AlTa-96Du-LB.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AlTa-96Du-LB.json) |
| AlTa-98Sau.tdb | N. Saunders, COST 507, Final report round 2, 1998. | `790811d9dcc140fcdf7588bfa4873178564f71350062bbe75849a62e6974132c` | [viewer](https://orchid-project.org/phase-diagrams/#AL-TA/AlTa-98Sau.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AlTa-98Sau.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AlTa-98Sau.json) |

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

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| AlTa-10Wit.tdb | 2346.46 | LIQUID (x(Ta) 0.6776) + SIGMA_D8B (x(Ta) 0.75882) + BCC_A2 (x(Ta) 0.93017) |
| AlTa-10Wit.tdb | 1884.72 | LIQUID (x(Ta) 0.32667) + AL69TA39 (x(Ta) 0.37818) + SIGMA_D8B (x(Ta) 0.50945) |
| AlTa-10Wit.tdb | 1814.46 | LIQUID (x(Ta) 0.23731) + AL3TA_D022 (x(Ta) 0.24406) + AL69TA39 (x(Ta) 0.35489) |
| AlTa-10Wit.tdb | 1728.41 | AL69TA39 (x(Ta) 0.37542) + SIGMA_D8B (x(Ta) 0.51069) + AL38TA48 (x(Ta) 0.52155) |
| AlTa-10Wit.tdb | 1371.45 | AL3TA_D022 (x(Ta) 0.24995) + AL69TA39 (x(Ta) 0.36795) + AL38TA48 (x(Ta) 0.52365) |
| AlTa-10Wit.tdb | 933.7 | LIQUID (x(Ta) 4.000e-5) + FCC_A1 (x(Ta) 3.800e-4) + AL3TA_D022 (x(Ta) 0.24736) |
| AlTa-10Wit.tdb | 933.7 | LIQUID (x(Ta) 4.000e-5) + FCC_A1 (x(Ta) 3.800e-4) + AL3TA_D022 (x(Ta) 0.24736) |
| AlTa-90Kat.tdb | 2378.58 | LIQUID (x(Ta) 0.57678) + SIGMA_D8B (x(Ta) 0.69621) + BCC_A2 (x(Ta) 0.95956) |
| AlTa-90Kat.tdb | 2037.05 | LIQUID (x(Ta) 0.3588) + ALTA (x(Ta) 0.51515) + SIGMA_D8B (x(Ta) 0.54172) |
| AlTa-90Kat.tdb | 2037.05 | LIQUID (x(Ta) 0.35875) + ALTA (x(Ta) 0.51515) + SIGMA_D8B (x(Ta) 0.54168) |
| AlTa-90Kat.tdb | 1867.6 | LIQUID (x(Ta) 0.28252) + AL2TA (x(Ta) 0.35) + ALTA (x(Ta) 0.51515) |
| AlTa-90Kat.tdb | 1867.6 | LIQUID (x(Ta) 0.28258) + AL2TA (x(Ta) 0.35) + ALTA (x(Ta) 0.51515) |
| AlTa-90Kat.tdb | 1867.6 | LIQUID (x(Ta) 0.28245) + AL2TA (x(Ta) 0.35) + ALTA (x(Ta) 0.51515) |
| AlTa-90Kat.tdb | 1824.1 | LIQUID (x(Ta) 0.23905) + AL3TA_D022 (x(Ta) 0.25) + AL2TA (x(Ta) 0.35) |
| AlTa-90Kat.tdb | 1824.1 | LIQUID (x(Ta) 0.23901) + AL3TA_D022 (x(Ta) 0.25) + AL2TA (x(Ta) 0.35) |
| AlTa-90Kat.tdb | 933.88 | LIQUID (x(Ta) 3.000e-5) + FCC_A1 (x(Ta) 6.300e-4) + AL3TA_D022 (x(Ta) 0.25) |
| AlTa-96Du-LB.tdb | 2334.16 | LIQUID (x(Ta) 0.63687) + SIGMA_D8B (x(Ta) 0.75611) + BCC_A2 (x(Ta) 0.91897) |
| AlTa-96Du-LB.tdb | 1820.86 | AL3TA_D022 (x(Ta) 0.25) + AL69TA39 (x(Ta) 0.36111) + LIQUID (x(Ta) 0.36665) |
| AlTa-96Du-LB.tdb | 1820.86 | AL3TA_D022 (x(Ta) 0.25) + AL69TA39 (x(Ta) 0.36111) + LIQUID (x(Ta) 0.36662) |
| AlTa-96Du-LB.tdb | 1820.86 | AL3TA_D022 (x(Ta) 0.25) + AL69TA39 (x(Ta) 0.36111) + LIQUID (x(Ta) 0.36658) |
| AlTa-96Du-LB.tdb | 1772.49 | AL69TA39 (x(Ta) 0.36111) + LIQUID (x(Ta) 0.45083) + SIGMA_D8B (x(Ta) 0.65052) |
| AlTa-96Du-LB.tdb | 1772.49 | AL69TA39 (x(Ta) 0.36111) + LIQUID (x(Ta) 0.45086) + SIGMA_D8B (x(Ta) 0.65053) |
| AlTa-96Du-LB.tdb | 1718.94 | AL69TA39 (x(Ta) 0.36111) + ALTA (x(Ta) 0.5) + SIGMA_D8B (x(Ta) 0.65387) |
| AlTa-96Du-LB.tdb | 1718.94 | AL69TA39 (x(Ta) 0.36111) + ALTA (x(Ta) 0.5) + SIGMA_D8B (x(Ta) 0.65389) |
| AlTa-96Du-LB.tdb | 1618.38 | AL69TA39 (x(Ta) 0.36111) + AL7TA5 (x(Ta) 0.41667) + ALTA (x(Ta) 0.5) |
| AlTa-96Du-LB.tdb | 1498.65 | AL69TA39 (x(Ta) 0.36111) + AL3TA2 (x(Ta) 0.4) + AL7TA5 (x(Ta) 0.41667) |
| AlTa-96Du-LB.tdb | 1456.11 | AL3TA_D022 (x(Ta) 0.25) + AL69TA39 (x(Ta) 0.36111) + AL3TA2 (x(Ta) 0.4) |
| AlTa-96Du-LB.tdb | 935.02 | LIQUID (x(Ta) 2.500e-4) + FCC_A1 (x(Ta) 0.00252) + AL3TA_D022 (x(Ta) 0.25) |
| AlTa-96Du-LB.tdb | 935.02 | LIQUID (x(Ta) 2.400e-4) + FCC_A1 (x(Ta) 0.00247) + AL3TA_D022 (x(Ta) 0.25) |
| AlTa-98Sau.tdb | 2270.42 | LIQUID (x(Ta) 0.64336) + SIGMA_D8B (x(Ta) 0.72071) + BCC_A2 (x(Ta) 0.87743) |
| AlTa-98Sau.tdb | 1826.61 | AL3TA_D022 (x(Ta) 0.25) + LIQUID (x(Ta) 0.36615) + AL3TA2_H (x(Ta) 0.4) |
| AlTa-98Sau.tdb | 1826.61 | AL3TA_D022 (x(Ta) 0.25) + LIQUID (x(Ta) 0.36603) + AL3TA2_H (x(Ta) 0.4) |
| AlTa-98Sau.tdb | 1826.61 | AL3TA_D022 (x(Ta) 0.25) + LIQUID (x(Ta) 0.36578) + AL3TA2_H (x(Ta) 0.4) |
| AlTa-98Sau.tdb | 1819.76 | AL3TA2_H (x(Ta) 0.4) + LIQUID (x(Ta) 0.44412) + SIGMA_D8B (x(Ta) 0.57586) |
| AlTa-98Sau.tdb | 1819.76 | AL3TA2_H (x(Ta) 0.4) + LIQUID (x(Ta) 0.44418) + SIGMA_D8B (x(Ta) 0.57593) |
| AlTa-98Sau.tdb | 1498.13 | AL3TA2_L (x(Ta) 0.4) + AL3TA2_H (x(Ta) 0.4) + SIGMA_D8B (x(Ta) 0.57453) |
| AlTa-98Sau.tdb | 1498.13 | AL3TA_D022 (x(Ta) 0.25) + AL3TA2_L (x(Ta) 0.4) + AL3TA2_H (x(Ta) 0.4) |
| AlTa-98Sau.tdb | 1498.13 | AL3TA2_H (x(Ta) 0.4) + AL3TA2_L (x(Ta) 0.4) + SIGMA_D8B (x(Ta) 0.57453) |
| AlTa-98Sau.tdb | 934.02 | LIQUID (x(Ta) 7.000e-5) + FCC_A1 (x(Ta) 8.700e-4) + AL3TA_D022 (x(Ta) 0.25) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/AL/AL-TA.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/AL/AL-TA.json) · [CALPHAD hull AlTa-90Kat](https://data.orchid-project.org/hulls/calphad-sgte/AL/AL-TA--AlTa-90Kat.json) · [CALPHAD hull AlTa-96Du-LB](https://data.orchid-project.org/hulls/calphad-sgte/AL/AL-TA--AlTa-96Du-LB.json) · [CALPHAD hull AlTa-98Sau](https://data.orchid-project.org/hulls/calphad-sgte/AL/AL-TA--AlTa-98Sau.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Al–Ta system (50)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 2373 | peritectic: L + β -> σ |  | experimental | [1] Witusiewicz 2010; _cites Wilhelm 1962_ | Table 4, p. 10, row 1; `ORC-2TQEE44HKH` |  |
| 2373 | peritectic: Liquid + bcc (Ta) \<-> σAlTa2 | σAlTa2: Al 0.333333, Ta 0.666667 | experimental | [2] Du 1996; _cites ref. 62Wil_ | Table 6, p. 7, row 1; `ORC-R6LUOWZHON` |  |
| 2353 | peritectic: Liquid + bcc (Ta) \<-> σAlTa2 | Liquid: Ta 0.625; bcc (Ta): Ta 0.93; σAlTa2: Al 0.333333, Ta 0.666667 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 3; `ORC-KQYOIZT364` |  |
| 2353 | peritectic: L + β -> σ |  | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 3; `ORC-RTEFXHOWFJ` |  |
| 2347 | peritectic: L + β -> σ | L: Ta 0.678; β: Ta 0.93; σ: Ta 0.759 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 5; `ORC-WSBPU2HJJR` |  |
| 2334 | peritectic: Liquid + bcc (Ta) \<-> σAlTa2 | Liquid: Ta 0.637; bcc (Ta): Ta 0.92; σAlTa2: Ta 0.76 | model | [2] Du 1996 | Table 6, p. 7, row 4; `ORC-TNLOHVFZ2L` |  |
| 2334 | peritectic: L + β -> σ | L: Ta 0.637; β: Ta 0.92; σ: Ta 0.76 | model | [1] Witusiewicz 2010; _cites Du 1996_ [doi](https://doi.org/10.1007/bf02665557) | Table 4, p. 10, row 4; `ORC-ZDPWQ5SIYC` |  |
| 2275 | peritectic: L + β -> σ | L: Ta 0.63; β: Ta 0.88; σ: Ta 0.667 | experimental | [1] Witusiewicz 2010; _cites Kimura 2006_ | Table 4, p. 10, row 2; `ORC-CTQBGESW77` |  |
| 2275 | peritectic: Liquid + bcc (Ta) \<-> σAlTa2 | Liquid: Ta 0.63; bcc (Ta): Ta 0.88; σAlTa2: Ta 0.667 | experimental | [2] Du 1996; _cites ref. 73Kim_ | Table 6, p. 7, row 2; `ORC-ESHDLT5MAV` |  |
| 2270.4 | peritectic: Liquid + bcc-A2 -> σ | Liquid: Ta 0.643; bcc-A2: Ta 0.877; σ: Ta 0.72 | model | [3] (ed.) 1998 | Table I, p. 103, row 4; `ORC-AAI6DJGYFJ` |  |
| 1901 | congruent melting: Al3Ta\* -> Liquid | Al3Ta\*: Ta 0.25; Liquid: Ta 0.25 | model | [3] (ed.) 1998 | Table I, p. 103, row 5; `ORC-JWLZMFS667` |  |
| 1900 | congruent melting: Liquid \<-> Al3Ta | Liquid: Ta 0.25; Al3Ta: Ta 0.25 | experimental | [2] Du 1996; _cites ref. 85Sch_ | Table 6, p. 7, row 22; `ORC-CHHBCJPQ2F` |  |
| 1888 | congruent melting: Liquid \<-> Al3Ta | Liquid: Ta 0.25; Al3Ta: Ta 0.25 | experimental | [2] Du 1996; _cites ref. 96Sch_ | Table 6, p. 7, row 24; `ORC-LPSM53SBJK` |  |
| 1885 | peritectic: L + σ -> Ta39Al69 | L: Ta 0.327; σ: Ta 0.51; Ta39Al69: Ta 0.378 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 7; `ORC-K3C65SVRYY` |  |
| 1883 | peritectic: L + σ -> Ta39Al69 | σ: Ta 0.512; Ta39Al69: Ta 0.376 | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 6; `ORC-L43EHLAPSG` |  |
| 1881 | congruent melting: Liquid \<-> Al3Ta | Liquid: Ta 0.25; Al3Ta: Ta 0.25 | model | [2] Du 1996 | Table 6, p. 7, row 25; `ORC-ZT6WOTHV6U` |  |
| 1865 | congruent melting: Liquid \<-> Al3Ta | Liquid: Ta 0.25; Al3Ta: Ta 0.25 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 23; `ORC-2IO6LDJVFI` |  |
| 1854 | congruent transformation: σ -> φ | σ: Ta 0.552; φ: Ta 0.552 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 8; `ORC-AUAYL2VDSC` |  |
| 1840 | peritectic: Liquid + Al3Ta \<-> Al69Ta39 | Liquid: Ta 0.39; Al3Ta: Ta 0.25; Al69Ta39: Ta 0.4 | experimental | [2] Du 1996; _cites ref. 85Sch_ | Table 6, p. 7, row 5; `ORC-IPEWA3KR76` |  |
| 1826.8 | eutectic: Liquid -> + AlM-D0\*22 + Al3Ta2-II | Liquid: Ta 0.366; AlM-D0\*22: Ta 0.25; Al3Ta2-II: Ta 0.4 | model | [3] (ed.) 1998 | Table I, p. 103, row 2; `ORC-6QCSSLXJXL` |  |
| 1824 | peritectic |  | experimental | [1] Witusiewicz 2010; _cites Subramanian 1990_ [doi](https://doi.org/10.1007/bf02671926) | p. 3; `ORC-VTHW4HJFNV.5b97ba` | “In the literature there are both variants of melting for the 3-phase, congruent at 1823 \[23\] or 1900 K \[20\] and peritectic at 1773 \[44\] or 1824 K \[14\].” |
| 1822 | peritectic: L + Ta39Al69 -> ε | Ta39Al69: Ta 0.359; ε: Ta 0.249 | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 9; `ORC-ZUBACZFP2G` |  |
| 1821 | peritectic: Liquid + Al3Ta \<-> Al69Ta39 | Liquid: Ta 0.37; Al3Ta: Ta 0.25; Al69Ta39: Ta 0.361 | model | [2] Du 1996 | Table 6, p. 7, row 7; `ORC-SY5CYR4JFH` |  |
| 1820 | eutectic: Liquid \<-> Al69Ta39 + AlTa2 | Liquid: Ta 0.43; Al69Ta39: Ta 0.4; AlTa2: Al 0.333333, Ta 0.666667 | experimental | [2] Du 1996; _cites ref. 85Sch_ | Table 6, p. 7, row 9; `ORC-L666P6CASG` |  |
| 1819.8 | eutectic: Liquid -> Al3Ta2-H -> + σ | Liquid: Ta 0.444; Al3Ta2-H: Ta 0.4; σ: Ta 0.576 | model | [3] (ed.) 1998 | Table I, p. 103, row 3; `ORC-QFSAYDSARW` |  |
| 1814 | peritectic: L + Ta39Al69 -> ε | L: Ta 0.237; Ta39Al69: Ta 0.355; ε: Ta 0.244 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 10; `ORC-YKVRTRPUWM` |  |
| 1812 | peritectic: Liquid + Al3Ta \<-> Al69Ta39 | Liquid: Ta 0.42; Al3Ta: Ta 0.25; Al69Ta39: Ta 0.361 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 6; `ORC-LP26ZVN6WJ` |  |
| 1776 | eutectic: Liquid \<-> Al69Ta39 + AlTa2 | Liquid: Ta 0.45; Al69Ta39: Ta 0.361; AlTa2: Ta 0.64 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 10; `ORC-BJC3N6LQSD` |  |
| 1773 | eutectic: Liquid \<-> Al69Ta39 + AlTa2 | Liquid: Ta 0.42; Al69Ta39: Ta 0.25; AlTa2: Ta 0.667 | experimental | [2] Du 1996; _cites ref. 73Kim_ | Table 6, p. 7, row 8; `ORC-BL5V7NPVST` |  |
| 1772 | eutectic: Liquid \<-> Al69Ta39 + AlTa2 | Liquid: Ta 0.45; Al69Ta39: Ta 0.361; AlTa2: Ta 0.65 | model | [2] Du 1996 | Table 6, p. 7, row 11; `ORC-57ZGWJRCQV` |  |
| 1737 | eutectoid: σ -> Ta39Al69 + φ | σ: Ta 0.511; Ta39Al69: Ta 0.376; φ: Ta 0.522 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 12; `ORC-YEZSSVSREV` |  |
| 1733 | eutectoid: σ -> Ta39Al69 + φ | σ: Ta 0.51; Ta39Al69: Ta 0.361; φ: Al 0.44186, Ta 0.55814 | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 11; `ORC-4C3LNAWLLP` |  |
| 1720 | peritectoid: Al69Ta39 + AlTa2 \<-> AlTa | Al69Ta39: Ta 0.361; AlTa2: Ta 0.65; AlTa: Ta 0.5 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 12; `ORC-7JORJ4UJL6` |  |
| 1719 | peritectoid: Al69Ta39 + AlTa2 \<-> AlTa | Al69Ta39: Ta 0.361; AlTa2: Ta 0.65; AlTa: Ta 0.5 | model | [2] Du 1996 | Table 6, p. 7, row 13; `ORC-OAZKAQG7XT` |  |
| 1620 | peritectoid: Al69Ta39 + AlTa \<-> Al7Ta5 | Al69Ta39: Ta 0.361; AlTa: Ta 0.5; Al7Ta5: Ta 0.416 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 14; `ORC-OQ5MXMDICM` |  |
| 1618 | peritectoid: Al69Ta39 + AlTa \<-> Al7Ta5 | Al69Ta39: Ta 0.361; AlTa: Ta 0.5; Al7Ta5: Ta 0.416 | model | [2] Du 1996 | Table 6, p. 7, row 15; `ORC-NGUSR3DH6X` |  |
| 1500 | peritectoid: Al69Ta39 + Al7Ta5 \<-> Al3Ta2 | Al69Ta39: Ta 0.361; Al7Ta5: Ta 0.416; Al3Ta2: Ta 0.4 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 16; `ORC-5P3BEZZA46` |  |
| 1499 | peritectoid: Al69Ta39 + Al7Ta5 \<-> Al3Ta2 | Al69Ta39: Ta 0.361; Al7Ta5: Ta 0.416; Al3Ta2: Ta 0.4 | model | [2] Du 1996 | Table 6, p. 7, row 17; `ORC-4RSLH3OOAQ` |  |
| 1498.1 | polymorphic: Al3Ta2-H -> Al3Ta2-II | Al3Ta2-H: Ta 0.4; Al3Ta2-II: Ta 0.4 | model | [3] (ed.) 1998 | Table I, p. 103, row 6; `ORC-OOG6CSYD3B` |  |
| 1456 | eutectoid: Al69Ta39 \<-> Al3Ta + Al3Ta2 | Al69Ta39: Ta 0.361; Al3Ta: Ta 0.25; Al3Ta2: Ta 0.4 | model | [2] Du 1996 | Table 6, p. 7, row 19; `ORC-OWG3EU4XYG` |  |
| 1450 | eutectoid: Al69Ta39 \<-> Al3Ta + Al3Ta2 | Al69Ta39: Ta 0.361; Al3Ta: Ta 0.25; Al3Ta2: Ta 0.4 | experimental | [2] Du 1996; _cites ref. 95Mah_ | Table 6, p. 7, row 18; `ORC-2NIV2LZGPJ` |  |
| 1371 | eutectoid: Ta39Al69 -> ε + φ | Ta39Al69: Ta 0.368; ε: Ta 0.25; φ: Ta 0.524 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 14; `ORC-MCR5E5Z2WS` |  |
| 1367 | eutectoid: Ta39Al69 -> ε + φ | Ta39Al69: Ta 0.356; ε: Ta 0.251; φ: Ta 0.512 | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 13; `ORC-GIMMJSMQAB` |  |
| 941 | peritectic: L + ε -> (αAl) | L: Ta 2.000e-4; ε: Ta 0.25; (αAl): Ta 3.700e-4 | experimental | [1] Witusiewicz 2010; _cites Glazov 1956_ | Table 4, p. 10, row 15; `ORC-ROOOKSGIAB` |  |
| 941 | peritectic: Liquid + Al3Ta \<-> fcc (Al) | Liquid: Ta 2.200e-4; Al3Ta: Ta 0.25; fcc (Al): Ta 3.700e-4 | experimental | [2] Du 1996; _cites ref. 56Gla_ | Table 6, p. 7, row 20; `ORC-Y2YJSO5TRY` |  |
| 935 | peritectic: Liquid + Al3Ta \<-> fcc (Al) | Liquid: Ta 2.500e-4; Al3Ta: Ta 0.25; fcc (Al): Ta 0.0045 | model | [2] Du 1996 | Table 6, p. 7, row 21; `ORC-BRURBURMMX` |  |
| 935 | peritectic: L + ε -> (αAl) | L: Ta 2.500e-4; ε: Ta 0.25; (αAl): Ta 0.0045 | model | [1] Witusiewicz 2010; _cites Du 1996_ [doi](https://doi.org/10.1007/bf02665557) | Table 4, p. 10, row 19; `ORC-GBWZ7QZH2O` |  |
| 934 | peritectic: Liquid + AlM-D0\*22 -> fcc-Al | Liquid: Ta 1.000e-5; AlM-D0\*22: Ta 0.25; fcc-Al: Ta 8.000e-4 | model | [3] (ed.) 1998 | Table I, p. 103, row 1; `ORC-ESE42TQ5B5` |  |
| 933.8 | peritectic: L + ε -> (αAl) |  | experimental | [1] Witusiewicz 2010 | Table 4, p. 10, row 18; `ORC-YOGMOPZ3TT` |  |
| 933.7 | peritectic: L + ε -> (αAl) | L: Ta 3.800e-5; ε: Ta 0.247; (αAl): Ta 3.800e-4 | model | [1] Witusiewicz 2010 | Table 4, p. 10, row 20; `ORC-FN6SX2LP67` |  |

## 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–Ta system (10)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Ta39Al69 | [Al23Ta13](https://data.orchid-project.org/compounds/Al23Ta13.html) | -25.9 kJ/mol-atom | 298.15 | model | -23.899 (mp-aaacrhpr) |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 2; `ORC-3END6IXWVP.82a915` |  |
| ε |  | -29.954 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 1; `ORC-QD7X25AAWF.689dba` |  |
| σ |  | -24.788 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 4; `ORC-NAJ5GPIB5R.f1dbd7` |  |
| σ |  | -23.622 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 5; `ORC-NK2OEGHRJH.d0d563` |  |
| σ |  | -22.394 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 6; `ORC-DQ4E5JX3BI.d6a932` |  |
| σ |  | -22.05 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 7; `ORC-WRBL2AS6C4.b1514d` |  |
| σ |  | -19.867 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 8; `ORC-CDME223J3K.a09145` |  |
| σ |  | -16.556 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 9; `ORC-UM2PBLRTLW.9d2855` |  |
| σ |  | -13.246 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 10; `ORC-3RDX6Y2ZV5.4c1bb6` |  |
| φ |  | -24.654 kJ/mol-atom | 298.15 | model |  |  | [1] Witusiewicz 2010 | Table 5, p. 11, row 3; `ORC-UWXPAOPY2K.3a747a` |  |

## Other properties

### Phase transition (67)

Table: Phase transition, Al–Ta system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 924 K | 924 | (αAl) + ε ↔ L + ε; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 3; `ORC-ZKCERRNWHU` |  |
| Phase transition | 933 K | 933 | (αAl) + ε ↔ L + ε; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 1; `ORC-5EYAKA66IV` |  |
| Phase transition | 933.7 K | 933.7 | (αAl) + ε ↔ L + ε; _alloy: Al 0.795, Ta 0.205_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 4; `ORC-GNC77QFZKQ` |  |
| Phase transition | 933.8 K | 933.8 | (αAl) + ε ↔ L + ε; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 2; `ORC-HKP62NSHIC` |  |
| Phase transition | 1353 K | 1353 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 30; `ORC-XKMXB7E24K` |  |
| Phase transition | 1355 K | 1355 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 41; `ORC-3I3EP7QA77` |  |
| Phase transition | 1371 K | 1371 | ε + φ ↔ Ta39Al69 + ε; _alloy: Al 0.692, Ta 0.308_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 9; `ORC-KJRD7V42LS` |  |
| Phase transition | 1371 K | 1371 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 17; `ORC-L6WWGR2V5W` |  |
| Phase transition | 1371 K | 1371 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.559, Ta 0.441_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 31; `ORC-S7A64HLLN3` |  |
| Phase transition | 1371 K | 1371 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.543, Ta 0.457_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 42; `ORC-WZAQKGQLXE` |  |
| Phase transition | 1372 K | 1372 | ε + φ ↔ Ta39Al69 + ε; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 8; `ORC-ZRTE3AUTX7` |  |
| Phase transition | 1387 K | 1387 | ε + φ ↔ Ta39Al69 + φ; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 16; `ORC-VYRZ5XQYJT` |  |
| Phase transition | 1498 K | 1498 | polymorphic | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | p. 3; `ORC-3LGTTH2XNB` | “Besides, Schuster \[20\] reported a polymorphism for the Ta39Al69-phase and a corresponding DTA arrest at 1498 K upon heating, which is not in sharp disagreement with the decomposition temperature in the interval 1273-1423 K.” |
| Phase transition | 1662 K | 1662 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 44; `ORC-OWJGSS5L6D` |  |
| Phase transition | 1716 K | 1716 | φ + σ ↔ σ; _alloy: Al 0.416, Ta 0.584_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 53; `ORC-PG5MJSGHYY` |  |
| Phase transition | 1725 K | 1725 | φ + σ ↔ σ; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 52; `ORC-SHDXFPM7JC` |  |
| Phase transition | 1727 K | 1727 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 43; `ORC-ERG33WIDMC` |  |
| Phase transition | 1737 K | 1737 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 18; `ORC-7ACB7ZXFMX` |  |
| Phase transition | 1737 K | 1737 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.543, Ta 0.457_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 45; `ORC-PSK5VCUE5G` |  |
| Phase transition | 1737 K | 1737 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.559, Ta 0.441_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 33; `ORC-VUB5A7PONS` |  |
| Phase transition | 1740 K | 1740 | Ta39Al69 + φ ↔ Ta39Al69 + σ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 32; `ORC-O3C72JESR5` |  |
| Phase transition | 1759 K | 1759 | Ta39Al69 + σ ↔ Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 20; `ORC-GOPMWV7EOE` |  |
| Phase transition | 1804 K | 1804 | L + ε ↔ L; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 6; `ORC-KJ7K55JQYU` |  |
| Phase transition | 1806 K | 1806 | Ta39Al69 + ε ↔ L + Ta39Al69; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 11; `ORC-NFCEC3J3EM` |  |
| Phase transition | 1810 K | 1810 | L + ε ↔ L; _alloy: Al 0.795, Ta 0.205_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 7; `ORC-ZDFPADFIRT` |  |
| Phase transition | 1814 K | 1814 | Ta39Al69 + ε ↔ L + Ta39Al69; _alloy: Al 0.692, Ta 0.308_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 12; `ORC-VWO4CWIMXX` |  |
| Phase transition | 1820 K | 1820 | Ta39Al69 + σ ↔ Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 19; `ORC-PA5VZ6IGTS` |  |
| Phase transition | 1822 K | 1822 | Ta39Al69 + ε ↔ L + Ta39Al69; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 10; `ORC-R6W3ELNAPF` |  |
| Phase transition | 1840 K | 1840 | peritectic: Al3Ta2; _alloy: Ta 0.4_ | unspecified | [2] Du 1996; _cites ref. 85Sch_ | Table I, p. 2, row 38; `ORC-SYGVH2SXYY` |  |
| Phase transition | 1848 K | 1848 (\<) | L + ε ↔ L; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 5; `ORC-SXSWYTTEEI` |  |
| Phase transition | 1855 K | 1855 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 47; `ORC-PKZDHKSIG4` |  |
| Phase transition | 1855 K | 1855 | Ta39Al69 ↔ L + Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 23; `ORC-ZJPKAPBWZ2` |  |
| Phase transition | 1862 K | 1862 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 36; `ORC-4UNIKNFV5Q` |  |
| Phase transition | 1874 K | 1874 | L + Ta39Al69 ↔ L; _alloy: Al 0.692, Ta 0.308_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 15; `ORC-A576ZAB6R2` |  |
| Phase transition | 1876 K | 1876 | L + Ta39Al69 ↔ L; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 13; `ORC-UP25JUITPO` |  |
| Phase transition | 1876 K | 1876 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 46; `ORC-4UJSZRO6WX` |  |
| Phase transition | 1877 K | 1877 | Ta39Al69 ↔ L + Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 21; `ORC-QQ7V4BQ6TU` |  |
| Phase transition | 1879 K | 1879 | L + Ta39Al69 ↔ L; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 14; `ORC-7W7BJ3EDQ5` |  |
| Phase transition | 1881 K | 1881 | Ta39Al69 ↔ L + Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 24; `ORC-2O5CPT66IM` |  |
| Phase transition | 1881 K | 1881 | Ta39Al69 ↔ L + Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 22; `ORC-7EKAZ534JP` |  |
| Phase transition | 1884 K | 1884 | L + Ta39Al69 ↔ L + σ; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 25; `ORC-7IDVQS5ST3` |  |
| Phase transition | 1885 K | 1885 | L + Ta39Al69 ↔ L + σ; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 26; `ORC-DSM3BCE4EQ` |  |
| Phase transition | 1885 K | 1885 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.543, Ta 0.457_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 48; `ORC-K25CCDOQH4` |  |
| Phase transition | 1885 K | 1885 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 34; `ORC-LNHSZALV37` |  |
| Phase transition | 1885 K | 1885 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.559, Ta 0.441_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 37; `ORC-OQLN6MAZSQ` |  |
| Phase transition | 1895 K | 1895 | Ta39Al69 + σ ↔ L + σ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 35; `ORC-EY53JSJD5Z` |  |
| Phase transition | 1900 K | 1900 | congruent transformation | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | p. 3; `ORC-VTHW4HJFNV.08d38b` | “In the literature there are both variants of melting for the 3-phase, congruent at 1823 \[23\] or 1900 K \[20\] and peritectic at 1773 \[44\] or 1824 K \[14\].” |
| Phase transition | 1972 K | 1972 | L + σ ↔ L; _alloy: Al 0.624, Ta 0.376_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 29; `ORC-WZHUF7HI2O` |  |
| Phase transition | 1973 K | 1973 (>) | Al3Ta; _alloy: Ta 0.25_ | unspecified | [2] Du 1996; _cites ref. 65Bea_ | Table I, p. 2, row 36; `ORC-JW7NZ6WVLH` |  |
| Phase transition | 1978 K | 1978 | L + σ ↔ L; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 27; `ORC-EASV6BYTC2` |  |
| Phase transition | 2002 K | 2002 | L + σ ↔ L; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 28; `ORC-QNHQBT6QRP` |  |
| Phase transition | 2063 K | 2063 | L + σ ↔ L; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 39; `ORC-YPBHDCAOCS` |  |
| Phase transition | 2063 K | 2063 | σ ↔ L + σ; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 55; `ORC-J67256JI7E` |  |
| Phase transition | 2064 K | 2064 | L + σ ↔ L; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 38; `ORC-AGFLYRMTI6` |  |
| Phase transition | 2074 K | 2074 | L + σ ↔ L; _alloy: Al 0.559, Ta 0.441_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 40; `ORC-R7FDSN2TFG` |  |
| Phase transition | 2097 K | 2097 | L + σ ↔ L; _alloy: Al 0.543, Ta 0.457_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 51; `ORC-M3Q2LMY5UK` |  |
| Phase transition | 2099 K | 2099 | σ ↔ L + σ; _alloy: Al 0.416, Ta 0.584_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 56; `ORC-2O7H53Q4OF` |  |
| Phase transition | 2111 K | 2111 | σ ↔ L + σ; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 54; `ORC-P5YWSGYYQA` |  |
| Phase transition | 2139 K | 2139 | L + σ ↔ L; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 49; `ORC-X2RKBAZYIE` |  |
| Phase transition | 2159 K | 2159 | L + σ ↔ L; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 50; `ORC-MITCPMD3B2` |  |
| Phase transition | 2164 K | 2164 | L + σ ↔ L; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 58; `ORC-EZZBQAOWQT` |  |
| Phase transition | 2251 K | 2251 | L + σ ↔ L; _alloy: Al 0.416, Ta 0.584_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 59; `ORC-TYGVT2BJFN` |  |
| Phase transition | 2257 K | 2257 | L + σ ↔ L; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 57; `ORC-3CQG4KHFVF` |  |
| Phase transition | 2347 K | 2347 | β + σ ↔ L + β; _alloy: Al 0.12, Ta 0.88_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 61; `ORC-EWYZHNYPLB` |  |
| Phase transition | 2353 K | 2353 | peritectic: AlTa2; _alloy: Ta 0.666667_ | unspecified | [2] Du 1996; _cites ref. 95Mah_ | Table I, p. 2, row 43; `ORC-RBP5EKJW36` |  |
| Phase transition | 2353 K | 2353 | β + σ ↔ L + β; _alloy: Al 0.12, Ta 0.88_ | experimental | [1] Witusiewicz 2010 | Table 3, p. 7, row 60; `ORC-IKAS4TSK3N` |  |
| Phase transition | 2980 K | 2980 | L + β ↔ L; _alloy: Al 0.12, Ta 0.88_ | unspecified | [1] Witusiewicz 2010 | Table 3, p. 7, row 62; `ORC-WBP5E4TDCP` |  |

### Phase equilibrium (24)

Table: Phase equilibrium, Al–Ta system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase assemblage |  |  | (αAl) + ε; _alloy: Al 0.795, Ta 0.205_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 1; `ORC-UXEMADD7RC` |  |
| Phase assemblage |  |  | Ta39Al69 + σ; _alloy: Al 0.55, Ta 0.45_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 15; `ORC-5VV7MAGJFE` |  |
| Phase assemblage |  |  | Ta39Al69 + σ; _alloy: Al 0.61, Ta 0.39_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 14; `ORC-LIEWK5WGWP` |  |
| Phase assemblage |  |  | Ta39Al69 + σ; _alloy: Al 0.535, Ta 0.465_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 16; `ORC-PKQN6K3KYE` |  |
| Phase assemblage |  |  | ε + Ta39Al69; _alloy: Al 0.67, Ta 0.33_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 13; `ORC-66UHROFTNW` |  |
| Phase assemblage |  |  | σ; _alloy: Al 0.415, Ta 0.585_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 17; `ORC-NNXVHRI5XW` |  |
| Phase assemblage |  | 933 | (aAl); _alloy: Ta 0.205_ | experimental | [1] Witusiewicz 2010 | p. 8; `ORC-ZYY4PEPVLE` | “As shown in Fig. 6 the sample with 20.5 at.% Ta starts to melt at 933 K that is related to the (aAl) phase.” |
| Phase assemblage |  | 1273 | 3 + 4; _alloy: Ta 0.304_ | experimental | [1] Witusiewicz 2010; _cites Chou 2006_ [doi](https://doi.org/10.1007/s11664-006-0179-9) | p. 3; `ORC-DTNC34ZIA3.3f20a6` | “In \[5\] the same phase constituents were identified by EPMA in the samples Al-30.4 at.% Ta and Al-40.3 at.% Ta after annealing at 1273 and 1173 K for 35 days (840 h).” |
| Phase assemblage |  | 1273 | 3 + 4; _alloy: Ta 0.403_ | experimental | [1] Witusiewicz 2010; _cites Chou 2006_ [doi](https://doi.org/10.1007/s11664-006-0179-9) | p. 3; `ORC-DTNC34ZIA3.527d8d` | “In \[5\] the same phase constituents were identified by EPMA in the samples Al-30.4 at.% Ta and Al-40.3 at.% Ta after annealing at 1273 and 1173 K for 35 days (840 h).” |
| Phase assemblage |  | 1373 | ε + Ta39Al69 + φ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 8; `ORC-DNKBEDFDHT` |  |
| Phase assemblage |  | 1423 | s; _alloy: Ta 0.601_ | experimental | [1] Witusiewicz 2010; _cites Subramanian 1990_ [doi](https://doi.org/10.1007/bf02671926) | p. 3; `ORC-CN3MH66HAQ.cffc50` | “In \[19\] the sample Al-64.2 at.% Ta annealed at w1510 K was shown in the two-phase field f þ s, while in \[14\] the alloy Al60.1 at.% Ta was single-phase s after annealing at both 1423 and 1673 K for 500 and 100 h, respectively.” |
| Phase assemblage |  | 1473 | Ta39Al69; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 5; `ORC-DAXXIDIQXF` |  |
| Phase assemblage |  | 1473 | ε + Ta39Al69; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 3; `ORC-DNWUSYMQK2` |  |
| Phase assemblage |  | 1473 | φ + σ; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 10; `ORC-NMPCJTWPSK` |  |
| Phase assemblage |  | 1510 | f + s; _alloy: Ta 0.642_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | p. 3; `ORC-CN3MH66HAQ.8e494d` | “In \[19\] the sample Al-64.2 at.% Ta annealed at w1510 K was shown in the two-phase field f þ s, while in \[14\] the alloy Al60.1 at.% Ta was single-phase s after annealing at both 1423 and 1673 K for 500 and 100 h, respectively.” |
| Phase assemblage |  | 1673 | s; _alloy: Ta 0.601_ | experimental | [1] Witusiewicz 2010; _cites Subramanian 1990_ [doi](https://doi.org/10.1007/bf02671926) | p. 3; `ORC-CN3MH66HAQ.91055b` | “In \[19\] the sample Al-64.2 at.% Ta annealed at w1510 K was shown in the two-phase field f þ s, while in \[14\] the alloy Al60.1 at.% Ta was single-phase s after annealing at both 1423 and 1673 K for 500 and 100 h, respectively.” |
| Phase assemblage |  | 1773 | ε + Ta39Al69; _alloy: Al 0.692, Ta 0.308_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 2; `ORC-P3IJI4LHJB` |  |
| Phase assemblage |  | 1833 | Ta39Al69 + σ; _alloy: Al 0.559, Ta 0.441_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 6; `ORC-EUPAMTRDCH` |  |
| Phase assemblage |  | 1833 | Ta39Al69 + σ; _alloy: Al 0.624, Ta 0.376_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 4; `ORC-R54HKGJFS5` |  |
| Phase assemblage |  | 1833 | Ta39Al69 + σ; _alloy: Al 0.543, Ta 0.457_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 7; `ORC-YPALWYPW6Q` |  |
| Phase assemblage |  | 2023 | σ; _alloy: Al 0.416, Ta 0.584_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 9; `ORC-2YOXARUDAZ` |  |
| Phase assemblage |  | 2273 | σ + β; _alloy: Ta 1_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 19; `ORC-2Y33XMTSTE` |  |
| Phase assemblage |  | 2273 | σ + β; _alloy: Al 0.12, Ta 0.88_ | experimental | [1] Witusiewicz 2010 | Table 2, p. 4, row 11; `ORC-Q67PVSDZZR` |  |
| Phase composition |  | 1823 | congruent melting: Al3Ta; _liquid: Ta 0.25; Al3Ta: Ta 0.25_ | unspecified | [2] Du 1996; _cites ref. 73Kim_ | Table I, p. 2, row 37; `ORC-PB2HBLXSSE` |  |

### Heat capacity / entropy / enthalpy (12)

Table: Heat capacity / entropy / enthalpy, Al–Ta system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: entropy at constant volume_ | 95.4 J K 1 mol 1 | 298.15 |  | DFT | [4] Gebauer 2022; _cites Online_ | p. 6; `ORC-7SOXEQPCAB` | “The entropy at constant volume of AlTaO4 is available in an online database for ab initio phonon calculations\[36\] and is 95.4 J K1 mol1 at 25 °C.” |
| Entropy; _printed: entropy at constant pressure_ | 95 J K 1 mol 1 | 298.15 |  | model | [4] Gebauer 2022 | p. 6; `ORC-VO6DXUD6L7` | “The entropy at constant pressure calculated from our dataset is 95.0 J K1 mol1 at 25 °C.” |
| Entropy; _printed: Δ298S_ | -3.506 J K^-1 mol^-1 per mol-atom | 298.15 | Ta39Al69; _alloy: Ta 0.361111_ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 2; `ORC-3END6IXWVP.2afff1` |  |
| Entropy; _printed: Δ298S_ | -5.688 J K^-1 mol^-1 per mol-atom | 298.15 | ε | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 1; `ORC-QD7X25AAWF.6c54ec` |  |
| Entropy; _printed: Δ298S_ | -0.969 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 10; `ORC-3RDX6Y2ZV5.58387f` |  |
| Entropy; _printed: Δ298S_ | -2.122 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 8; `ORC-CDME223J3K.ac6e2e` |  |
| Entropy; _printed: Δ298S_ | -2.58 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 6; `ORC-DQ4E5JX3BI.322ff4` |  |
| Entropy; _printed: Δ298S_ | -2.611 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 4; `ORC-NAJ5GPIB5R.222b63` |  |
| Entropy; _printed: Δ298S_ | -2.542 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 5; `ORC-NK2OEGHRJH.719f38` |  |
| Entropy; _printed: Δ298S_ | -1.37 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 9; `ORC-UM2PBLRTLW.acd1c1` |  |
| Entropy; _printed: Δ298S_ | -3.071 J K^-1 mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 7; `ORC-WRBL2AS6C4.a72294` |  |
| Entropy; _printed: Δ298S_ | -2.515 J K^-1 mol^-1 per mol-atom | 298.15 | φ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 3; `ORC-UWXPAOPY2K.62ad51` |  |

### Activity / EMF / Gibbs energy (10)

Table: Activity / EMF / Gibbs energy, Al–Ta system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy; _printed: Δ298G_ | -24850 J mol^-1 per mol-atom | 298.15 | Ta39Al69; _alloy: Ta 0.361111_ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 2; `ORC-3END6IXWVP.e1d415` |  |
| Gibbs energy; _printed: Δ298G_ | -27986 J mol^-1 per mol-atom | 298.15 | ε | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 1; `ORC-QD7X25AAWF.ab66d8` |  |
| Gibbs energy; _printed: Δ298G_ | -12951 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 10; `ORC-3RDX6Y2ZV5.de6ea4` |  |
| Gibbs energy; _printed: Δ298G_ | -19229 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 8; `ORC-CDME223J3K.7c632b` |  |
| Gibbs energy; _printed: Δ298G_ | -21619 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 6; `ORC-DQ4E5JX3BI.103b49` |  |
| Gibbs energy; _printed: Δ298G_ | -24005 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 4; `ORC-NAJ5GPIB5R.7ae356` |  |
| Gibbs energy; _printed: Δ298G_ | -22859 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 5; `ORC-NK2OEGHRJH.23e00f` |  |
| Gibbs energy; _printed: Δ298G_ | -16142 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 9; `ORC-UM2PBLRTLW.403d81` |  |
| Gibbs energy; _printed: Δ298G_ | -21129 J mol^-1 per mol-atom | 298.15 | σ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 7; `ORC-WRBL2AS6C4.cc61f8` |  |
| Gibbs energy; _printed: Δ298G_ | -23900 J mol^-1 per mol-atom | 298.15 | φ | model | [1] Witusiewicz 2010 | Table 5, p. 11, row 3; `ORC-UWXPAOPY2K.25e2bb` |  |

### Crystal structure (52)

Table: Crystal structure, Al–Ta system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 11.0715 Å |  | Ta2Al3(ht); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 12; `ORC-E5FPNUAM6A.dd4507` |  |
| Lattice a | 3.296 Å |  | β, (Ta), bcc_A2; _alloy: Al 0.02, Ta 0.98_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 4; `ORC-OH6OI3XLKU` |  |
| Lattice a | 9.8707 Å ± 1.000e-4 |  | φ, Ta48Al38 (β); _alloy: Ta 0.55814_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 17; `ORC-CXJT6CEQEE.ff15b8` |  |
| Lattice a | 4.0496 Å | 298.15 | (αAl), fcc_A1; _alloy: Ta 0_ | experimental | [1] Witusiewicz 2010; _cites 3 vols 1990_ | Table 1, p. 2, row 1; `ORC-2JR5H5LMZ3` |  |
| Lattice a | 4.053 Å | 298.15 | (αAl), fcc_A1; _alloy: Al 0.99964, Ta 3.600e-4_ | experimental | [1] Witusiewicz 2010; _cites Glazov 1956_ | Table 1, p. 2, row 2; `ORC-GGN46U6Q4N` |  |
| Lattice a | 19.315 Å | 298.15 | Ta12Al17; _alloy: Ta 0.413793_ | experimental | [1] Witusiewicz 2010; _cites Raman 1965_ | Table 1, p. 2, row 11; `ORC-CNEMSGSKUL` |  |
| Lattice a | 9.88 Å | 298.15 | Ta17Al12; _alloy: Ta 0.586207_ | experimental | [1] Witusiewicz 2010; _cites Raman 1965_ | Table 1, p. 2, row 19; `ORC-32L36HKMTL` |  |
| Lattice a | 12.776 Å ± 0.005 | 298.15 | Ta2Al3; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Girgis 1970_ [doi](https://doi.org/10.1007/bf01010264) | Table 1, p. 2, row 13; `ORC-YXIQSBLQKO.4d153c` |  |
| Lattice a | 15.5614 Å | 298.15 | Ta2Al3(lt); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 15; `ORC-OIQDCJDFOD.6f414c` |  |
| Lattice a | 10.748 Å | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.b08539` |  |
| Lattice a | 19.172 Å | 298.15 | Ta39Al69; _alloy: Ta 0.361111_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 9; `ORC-P4BSEO2UKO` |  |
| Lattice a | 19.153 Å ± 0.001 | 298.15 | Ta39Al69; _alloy: Ta 0.361111_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1994_ [doi](https://doi.org/10.1016/0925-8388%2894%2990746-3) | Table 1, p. 2, row 8; `ORC-ZZK2SBJHOS` |  |
| Lattice a | 32.14 Å ± 0.02 | 298.15 | Ta5Al7, AlvTa v ≈ 1.4; _alloy: Ta 0.416667_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 16; `ORC-GBUKQUKW74.3b8d4a` |  |
| Lattice a | 14.865 Å ± 0.003 | 298.15 | TaAl; _alloy: Ta 0.5_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990879-r) | Table 1, p. 2, row 18; `ORC-MCOEWU2D2Q.0698d7` |  |
| Lattice a | 19.157 Å ± 0.002 | 298.15 | TaAl2; _alloy: Ta 0.333333_ | experimental | [1] Witusiewicz 2010; _cites Subramanian 1990_ [doi](https://doi.org/10.1007/bf02671926) | Table 1, p. 2, row 10; `ORC-3SSKRXPLOV` |  |
| Lattice a | 3.8488 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Schuhmacher 1990_ | Table 1, p. 2, row 6; `ORC-A7BUNK4HHB.bcf56d` |  |
| Lattice a | 3.834 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Brauer 1938_ [doi](https://doi.org/10.1007/bf01590179) | Table 1, p. 2, row 5; `ORC-OUTMALIKNJ.2f3967` |  |
| Lattice a | 3.839 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 7; `ORC-UOQLJ2ZHWR.46d984` |  |
| Lattice a | 9.891 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.35, Ta 0.65_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 23; `ORC-7SSTKUKLN7.f3394c` |  |
| Lattice a | 9.942 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.276, Ta 0.724_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 24; `ORC-AP5FUDXFJ7.0eae2f` |  |
| Lattice a | 10.014 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.24, Ta 0.76_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 26; `ORC-BDA6IQA4CO.1a3e40` |  |
| Lattice a | 9.828 Å | 298.15 | σ, Ta2Al; _alloy: Ta 0.666667_ | experimental | [1] Witusiewicz 2010; _cites Edshammar 1960_ [doi](https://doi.org/10.3891/acta.chem.scand.14-1219) | Table 1, p. 2, row 20; `ORC-EHPZJDAMFR.524f91` |  |
| Lattice a | 9.845 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.39, Ta 0.61_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 22; `ORC-OZSSPNXCWB.fb903f` |  |
| Lattice a | 9.957 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.26, Ta 0.74_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 25; `ORC-QVUVRGBHO7.39cc15` |  |
| Lattice a | 9.842 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.4, Ta 0.6_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 21; `ORC-U5LEVXJENO.6c3986` |  |
| Lattice b | 6.8717 Å |  | Ta2Al3(ht); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 12; `ORC-E5FPNUAM6A.1f6f0b` |  |
| Lattice b | 9.8766 Å ± 1.000e-4 |  | φ, Ta48Al38 (β); _alloy: Ta 0.55814_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 17; `ORC-CXJT6CEQEE.d5088a` |  |
| Lattice b | 13.947 Å | 298.15 | Ta2Al3(lt); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 15; `ORC-OIQDCJDFOD.ef06bd` |  |
| Lattice b | 11.078 Å | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.ae4453` |  |
| Lattice b | 9.863 Å ± 0.002 | 298.15 | TaAl; _alloy: Ta 0.5_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990879-r) | Table 1, p. 2, row 18; `ORC-MCOEWU2D2Q.db426c` |  |
| Lattice c | 4.7945 Å |  | Ta2Al3(ht); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 12; `ORC-E5FPNUAM6A.58ea79` |  |
| Lattice c | 16.3539 Å ± 2.000e-4 |  | φ, Ta48Al38 (β); _alloy: Ta 0.55814_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 17; `ORC-CXJT6CEQEE.be6582` |  |
| Lattice c | 27.04 Å ± 0.04 | 298.15 | Ta2Al3; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Girgis 1970_ [doi](https://doi.org/10.1007/bf01010264) | Table 1, p. 2, row 13; `ORC-YXIQSBLQKO.74e217` |  |
| Lattice c | 12.6628 Å | 298.15 | Ta2Al3(lt); _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 15; `ORC-OIQDCJDFOD.9a9799` |  |
| Lattice c | 10.433 Å | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.0acf88` |  |
| Lattice c | 13.41 Å ± 0.01 | 298.15 | Ta5Al7, AlvTa v ≈ 1.4; _alloy: Ta 0.416667_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 16; `ORC-GBUKQUKW74.cae2c1` |  |
| Lattice c | 9.862 Å ± 0.002 | 298.15 | TaAl; _alloy: Ta 0.5_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990879-r) | Table 1, p. 2, row 18; `ORC-MCOEWU2D2Q.afe959` |  |
| Lattice c | 8.5982 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Schuhmacher 1990_ | Table 1, p. 2, row 6; `ORC-A7BUNK4HHB.40e8d1` |  |
| Lattice c | 8.536 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Brauer 1938_ [doi](https://doi.org/10.1007/bf01590179) | Table 1, p. 2, row 5; `ORC-OUTMALIKNJ.d1c0bb` |  |
| Lattice c | 8.535 Å | 298.15 | ε, TaAl3; _alloy: Ta 0.25_ | experimental | [1] Witusiewicz 2010; _cites Schuster 1985_ | Table 1, p. 2, row 7; `ORC-UOQLJ2ZHWR.a692bd` |  |
| Lattice c | 5.198 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.35, Ta 0.65_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 23; `ORC-7SSTKUKLN7.c99149` |  |
| Lattice c | 5.198 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.276, Ta 0.724_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 24; `ORC-AP5FUDXFJ7.7e50c7` |  |
| Lattice c | 5.211 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.24, Ta 0.76_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 26; `ORC-BDA6IQA4CO.de41cc` |  |
| Lattice c | 5.232 Å | 298.15 | σ, Ta2Al; _alloy: Ta 0.666667_ | experimental | [1] Witusiewicz 2010; _cites Edshammar 1960_ [doi](https://doi.org/10.3891/acta.chem.scand.14-1219) | Table 1, p. 2, row 20; `ORC-EHPZJDAMFR.5a2963` |  |
| Lattice c | 5.217 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.39, Ta 0.61_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 22; `ORC-OZSSPNXCWB.8f69b6` |  |
| Lattice c | 5.199 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.26, Ta 0.74_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 25; `ORC-QVUVRGBHO7.412091` |  |
| Lattice c | 5.217 Å ± 0.001 | 298.15 | σ, Ta2Al; _alloy: Al 0.4, Ta 0.6_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 21; `ORC-U5LEVXJENO.43d4bf` |  |
| lattice alpha | 90.45 ° | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.ffe2d9` |  |
| lattice beta | 116.478 ° ± 0.001 |  | φ, Ta48Al38 (β); _alloy: Ta 0.55814_ | experimental | [1] Witusiewicz 2010; _cites Boulineau_ [doi](https://doi.org/10.1016/j.jssc.2006.07.001) | Table 1, p. 2, row 17; `ORC-CXJT6CEQEE.0383d1` |  |
| lattice beta | 97.6 ° | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.d36ada` |  |
| lattice beta | 99.98 ° ± 0.02 | 298.15 | TaAl; _alloy: Ta 0.5_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1993_ [doi](https://doi.org/10.1016/0925-8388%2893%2990879-r) | Table 1, p. 2, row 18; `ORC-MCOEWU2D2Q.be042c` |  |
| lattice gamma | 63.19 ° | 298.15 | Ta2Al3, AluTa u ≈ 1.5; _alloy: Ta 0.4_ | experimental | [1] Witusiewicz 2010; _cites Mahne 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2901411-6) | Table 1, p. 2, row 14; `ORC-FDSDHFKHGS.29c082` |  |

## Sources

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

1. V.T. Witusiewicz, A.A. Bondar, U. Hecht, J. Zollinger, V.M. Petyukh, O.S. Fomichov et al., Experimental study and thermodynamic re-assessment of the binary Al–Ta system, Intermetallics 18, 92-106 (2010). [doi:10.1016/j.intermet.2009.06.015](https://doi.org/10.1016/j.intermet.2009.06.015)
2. Y. Du, R. Schmid-Fetzer, Thermodynamic modeling of the Al-Ta system, JPE 17, 311-324 (1996). [doi:10.1007/bf02665557](https://doi.org/10.1007/bf02665557)
3. I. Ansara, A. T. Dinsdale, M. H. Rand (eds.), COST 507: Thermochemical database for light metal alloys, Volume 2, EUR 18499 EN, Office for Official Publications of the European Communities, Luxembourg (1998), ISBN 92-828-3902-8.
4. Julian Gebauer, Peter Franke, Hans Jürgen Seifert, Thermodynamic Evaluation of the system Ta–O and Preliminary Assessment of the Systems Al–Nb–O and Al–Ta–O, Adv Eng Mater 24 (2022). [doi:10.1002/adem.202200162](https://doi.org/10.1002/adem.202200162)

## 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/).