Ta–V phases

6 phases (tier A 5, liquid 1); 4 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: interactive registry · full JSON · Ta–V system page · Markdown · field reference

Phases of the Ta–V system (6)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
BCC_A2 phase:ta-v:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 5 of 5 calculated diagram(s): 300–3999.25 K, x(V) 0–1	23	5
C14_LAVES phase:ta-v:c14-laves	MgZn2 · C14 · hP12 · P6_3/mmc (194)	tier A: standard phase name	stable in 4 of 4 calculated diagram(s): 300–1705.03 K, x(V) 0.63798–0.69321	0	4
C15_LAVES phase:ta-v:c15-laves	Cu2Mg · C15 · cF24 · Fd-3m (227)	tier A: standard phase name	stable in 5 of 5 calculated diagram(s): 300–1576.32 K, x(V) 0.59861–0.68709	8	5
FCC_A1 phase:ta-v:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 5 calculated diagram(s)	0	5
HCP_A3 phase:ta-v:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 5 calculated diagram(s)	0	5
LIQUID phase:ta-v:liquid	liquid	liquid	stable in 5 of 5 calculated diagram(s): 2099.02–4000 K, x(V) 0–1	7	5

BCC_A2 (Ta–V)

Id: phase:ta-v:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stability: stable in 5 of 5 calculated diagram(s): 300–3999.25 K, x(V) 0–1
Literature: 23 values (23 accepted) from 2 papers
Interactive: phase registry entry

Names (8): corpus: corpus:phase:ta-v:bcc-a2
paper: paper:10.1016/j.calphad.2010.12.002:NM BCC Ta, paper:10.1016/s0925-8388(03)00728-x:bcc
tdb: tdb:TaV-04Dan-LB.tdb:BCC_A2, tdb:TaV-04Dan-final.tdb:BCC_A2, tdb:TaV-11Pav-3sl.tdb:BCC_A2, tdb:TaV-11Pav.tdb:BCC_A2, tdb:TaV-13Bro.tdb:BCC_A2

TDB models of BCC_A2 (5): PHASE and CONSTITUENT statements as written

TaV-04Dan-LB.tdb: BCC_A2, type code %B, sha256 759e7fab83f6768c…

34: PHASE BCC_A2 %B 2 1 3 !
35: CONST BCC_A2 : TA% V% : VA : !

TaV-04Dan-final.tdb: BCC_A2, type code %B, sha256 e087735be882c734…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : TA% V% : VA : !

TaV-11Pav-3sl.tdb: BCC_A2, type code %B, sha256 14fb4f3a13ba57e1…

34: PHASE BCC_A2 %B 2 1 3 !
35: CONST BCC_A2 : TA% V% : VA : !

TaV-11Pav.tdb: BCC_A2, type code %B, sha256 773e8a82344b28f3…

32: PHASE BCC_A2 %B 2 1 3 !
33: CONST BCC_A2 : TA% V% : VA : !

TaV-13Bro.tdb: BCC_A2, type code %B, sha256 f220800583236b2b…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : TA% V% : VA : !

Example references (5 of 5; assessments first):

doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase; reports values for this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1007/bf02868668 J. F. Smith, O. N. Carlson, The Ta-V (Tantalum-Vanadium) system, Bulletin of Alloy Phase Diagrams 4, 284-289 (1983).
cited as the source of values for this phase
doi:10.1016/0364-5916(91)90004-4 Lany Kaufman, Coupled thermochemical and phase diagram data for tantalum based binary alloys, Calphad 15, 243-259 (1991).
cited as the source of values for this phase

C14_LAVES (Ta–V)

Id: phase:ta-v:c14-laves; status assigned
Structure: MgZn2 · C14 · hP12 · P6_3/mmc (194); type st:c14-mgzn2-hp12; tier A: standard phase name; confidence high
Caveat: partitioned order/disorder model in TaV-04Dan-final.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-11Pav-3sl.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-11Pav.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-13Bro.tdb also describes the disordered state
Stability: stable in 4 of 4 calculated diagram(s): 300–1705.03 K, x(V) 0.63798–0.69321
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ta-v:c14-laves
tdb: tdb:TaV-04Dan-final.tdb:C14_LAVES, tdb:TaV-11Pav-3sl.tdb:C14_LAVES, tdb:TaV-11Pav.tdb:C14_LAVES, tdb:TaV-13Bro.tdb:C14_LAVES

TDB models of C14_LAVES (4): PHASE and CONSTITUENT statements as written

TaV-04Dan-final.tdb: C14_LAVES, type code %, sha256 e087735be882c734…

46: PHASE C14_LAVES % 2 2 1 !
47: CONST C14_LAVES : TA V% : TA% V : !

TaV-11Pav-3sl.tdb: C14_LAVES, type code %, sha256 14fb4f3a13ba57e1…

44: PHASE C14_LAVES % 3 2 6 4 !
45: CONST C14_LAVES : V : TA V% : TA% V : !

TaV-11Pav.tdb: C14_LAVES, type code %, sha256 773e8a82344b28f3…

42: PHASE C14_LAVES % 2 2 1 !
43: CONST C14_LAVES : TA V% : TA% V : !

TaV-13Bro.tdb: C14_LAVES, type code %, sha256 f220800583236b2b…

45: PHASE C14_LAVES % 2 2 1 !
46: CONST C14_LAVES : TA V% : TA% V : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase

C15_LAVES (Ta–V)

Id: phase:ta-v:c15-laves; status assigned
Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type st:c15-cu2mg-cf24; tier A: standard phase name; confidence high
Caveat: partitioned order/disorder model in TaV-04Dan-LB.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-04Dan-final.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-11Pav-3sl.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-11Pav.tdb also describes the disordered state
Caveat: partitioned order/disorder model in TaV-13Bro.tdb also describes the disordered state
Stability: stable in 5 of 5 calculated diagram(s): 300–1576.32 K, x(V) 0.59861–0.68709
Literature: 8 values (8 accepted) from 1 papers
Interactive: phase registry entry

Names (7): corpus: corpus:phase:ta-v:c15-laves
paper: paper:10.1016/s0925-8388(03)00728-x:C15
tdb: tdb:TaV-04Dan-LB.tdb:C15_LAVES, tdb:TaV-04Dan-final.tdb:C15_LAVES, tdb:TaV-11Pav-3sl.tdb:C15_LAVES, tdb:TaV-11Pav.tdb:C15_LAVES, tdb:TaV-13Bro.tdb:C15_LAVES

TDB models of C15_LAVES (5): PHASE and CONSTITUENT statements as written

TaV-04Dan-LB.tdb: C15_LAVES, type code %, sha256 759e7fab83f6768c…

44: PHASE C15_LAVES % 2 2 1 !
45: CONST C15_LAVES : TA V% : TA% V : !

TaV-04Dan-final.tdb: C15_LAVES, type code %, sha256 e087735be882c734…

51: PHASE C15_LAVES % 2 2 1 !
52: CONST C15_LAVES : TA V% : TA% V : !

TaV-11Pav-3sl.tdb: C15_LAVES, type code %, sha256 14fb4f3a13ba57e1…

49: PHASE C15_LAVES % 2 2 1 !
50: CONST C15_LAVES : TA V% : TA% V : !

TaV-11Pav.tdb: C15_LAVES, type code %, sha256 773e8a82344b28f3…

47: PHASE C15_LAVES % 2 2 1 !
48: CONST C15_LAVES : TA V% : TA% V : !

TaV-13Bro.tdb: C15_LAVES, type code %, sha256 f220800583236b2b…

50: PHASE C15_LAVES % 2 2 1 !
51: CONST C15_LAVES : TA V% : TA% V : !

Example references (4 of 4; assessments first):

doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1016/0364-5916(91)90004-4 Lany Kaufman, Coupled thermochemical and phase diagram data for tantalum based binary alloys, Calphad 15, 243-259 (1991).
cited as the source of values for this phase

FCC_A1 (Ta–V)

Id: phase:ta-v:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stability: not stable in 5 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:ta-v:fcc-a1
tdb: tdb:TaV-04Dan-LB.tdb:FCC_A1, tdb:TaV-04Dan-final.tdb:FCC_A1, tdb:TaV-11Pav-3sl.tdb:FCC_A1, tdb:TaV-11Pav.tdb:FCC_A1, tdb:TaV-13Bro.tdb:FCC_A1

TDB models of FCC_A1 (5): PHASE and CONSTITUENT statements as written

TaV-04Dan-LB.tdb: FCC_A1, type code %A, sha256 759e7fab83f6768c…

29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : TA V : VA : !

TaV-04Dan-final.tdb: FCC_A1, type code %A, sha256 e087735be882c734…

31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : TA V : VA : !

TaV-11Pav-3sl.tdb: FCC_A1, type code %A, sha256 14fb4f3a13ba57e1…

29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : TA V : VA : !

TaV-11Pav.tdb: FCC_A1, type code %A, sha256 773e8a82344b28f3…

27: PHASE FCC_A1 %A 2 1 1 !
28: CONST FCC_A1 : TA V : VA : !

TaV-13Bro.tdb: FCC_A1, type code %A, sha256 f220800583236b2b…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : TA V : VA : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase

HCP_A3 (Ta–V)

Id: phase:ta-v:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stability: not stable in 5 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:ta-v:hcp-a3
tdb: tdb:TaV-04Dan-LB.tdb:HCP_A3, tdb:TaV-04Dan-final.tdb:HCP_A3, tdb:TaV-11Pav-3sl.tdb:HCP_A3, tdb:TaV-11Pav.tdb:HCP_A3, tdb:TaV-13Bro.tdb:HCP_A3

TDB models of HCP_A3 (5): PHASE and CONSTITUENT statements as written

TaV-04Dan-LB.tdb: HCP_A3, type code %A, sha256 759e7fab83f6768c…

39: PHASE HCP_A3 %A 2 1 0.5 !
40: CONST HCP_A3 : TA V : VA : !

TaV-04Dan-final.tdb: HCP_A3, type code %A, sha256 e087735be882c734…

41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : TA V : VA : !

TaV-11Pav-3sl.tdb: HCP_A3, type code %A, sha256 14fb4f3a13ba57e1…

39: PHASE HCP_A3 %A 2 1 0.5 !
40: CONST HCP_A3 : TA V : VA : !

TaV-11Pav.tdb: HCP_A3, type code %A, sha256 773e8a82344b28f3…

37: PHASE HCP_A3 %A 2 1 0.5 !
38: CONST HCP_A3 : TA V : VA : !

TaV-13Bro.tdb: HCP_A3, type code %A, sha256 f220800583236b2b…

40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : TA V : VA : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase

LIQUID (Ta–V)

Id: phase:ta-v:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 5 of 5 calculated diagram(s): 2099.02–4000 K, x(V) 0–1
Literature: 7 values (7 accepted) from 1 papers
Interactive: phase registry entry

Names (8): corpus: corpus:phase:ta-v:liquid
paper: paper:10.1016/s0925-8388(03)00728-x:Liquid, paper:10.1016/s0925-8388(03)00728-x:liquid
tdb: tdb:TaV-04Dan-LB.tdb:LIQUID, tdb:TaV-04Dan-final.tdb:LIQUID, tdb:TaV-11Pav-3sl.tdb:LIQUID, tdb:TaV-11Pav.tdb:LIQUID, tdb:TaV-13Bro.tdb:LIQUID

TDB models of LIQUID (5): PHASE and CONSTITUENT statements as written

TaV-04Dan-LB.tdb: LIQUID, type code %, sha256 759e7fab83f6768c…

24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : TA V : !

TaV-04Dan-final.tdb: LIQUID, type code %, sha256 e087735be882c734…

26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : TA V : !

TaV-11Pav-3sl.tdb: LIQUID, type code %, sha256 14fb4f3a13ba57e1…

24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : TA V : !

TaV-11Pav.tdb: LIQUID, type code %, sha256 773e8a82344b28f3…

22: PHASE LIQUID:L % 1 1 !
23: CONST LIQUID:L : TA V : !

TaV-13Bro.tdb: LIQUID, type code %, sha256 f220800583236b2b…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : TA V : !

Example references (4 of 4; assessments first):

doi:10.1016/S0925-8388(03)00728-X C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2010.12.002 J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011).
assessment that models this phase
doi:10.1016/j.jssc.2012.12.003 P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013).
assessment that models this phase
doi:10.1007/bf02868668 J. F. Smith, O. N. Carlson, The Ta-V (Tantalum-Vanadium) system, Bulletin of Alloy Phase Diagrams 4, 284-289 (1983).
cited as the source of values for this phase

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735970
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite 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); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). 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.

@misc{orchid_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}