Fe–Te phases

10 phases (tier A 6, liquid 1, needs_review 3); 9 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 · Fe–Te system page · Markdown · field reference

Phases of the Fe–Te system (10)
Phase	Structure	Basis	Stability (calculated)	TDB models
HEXAGONAL_A8 phase:fe-te:a8-hexagonal	gamma-Se · A8 · hP3 · P3_121 (152)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–722.66 K, x(Te) 1–1	2
BCC_A2 phase:fe-te:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1865.92 K, x(Te) 0–0.01095	2
FCC_A1 phase:fe-te:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 1142.21–1702.21 K, x(Te) 0–0.00046	2
FETE_BETA_HT phase:fe-te:fete-beta		needs_review	stable in 2 of 2 calculated diagram(s): 1072.24–1185.14 K, x(Te) 0.461–0.48909	2
FETE_C38 phase:fe-te:fete-c38	Cu2Sb · C38 · tP6 · P4/nmm (129)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1117.04 K, x(Te) 0.44834–0.49076	2
FETE_DELTA phase:fe-te:fete-delta		needs_review	stable in 2 of 2 calculated diagram(s): 788.46–1084.69 K, x(Te) 0.55292–0.65624	2
FETE_GAMMA phase:fe-te:fete-gamma		needs_review	stable in 2 of 2 calculated diagram(s): 909.74–1080.24 K, x(Te) 0.54191–0.54191	2
FETE2_C18 phase:fe-te:fete2-c18	alpha-FeS2 · C18 · oP6 · Pnnm (58)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–925.49 K, x(Te) 0.66667–0.68192	2
HCP_A3 phase:fe-te:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 2 calculated diagram(s)	2
ION phase:fe-te:ion	liquid	liquid	stable in 2 of 2 calculated diagram(s): 720.08–2500 K, x(Te) 0–1	2

HEXAGONAL_A8 (Fe–Te)

Id: phase:fe-te:a8-hexagonal; status assigned
Structure: gamma-Se · A8 · hP3 · P3_121 (152); type st:a8-gamma-se-hp3; tier A: standard phase name; confidence high
Stoichiometry: Te 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 300–722.66 K, x(Te) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:fe-te:a8-hexagonal, corpus:phase:fe-te:hexagonal-a8
tdb: tdb:FeTe-18Arv.tdb:HEXAGONAL_A8, tdb:FeTe-19Arv.tdb:HEXAGONAL_A8

TDB models of HEXAGONAL_A8 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: HEXAGONAL_A8, type code %, sha256 3c9d8dd7e2fb4098…

52: PHASE HEXAGONAL_A8 % 1 1 !
53: CONST HEXAGONAL_A8 : TE : !

FeTe-19Arv.tdb: HEXAGONAL_A8, type code %, sha256 543d8ac5bac45cda…

51: PHASE HEXAGONAL_A8 % 1 1 !
52: CONST HEXAGONAL_A8 : TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

BCC_A2 (Fe–Te)

Id: phase:fe-te: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 2 of 2 calculated diagram(s): 300–1865.92 K, x(Te) 0–0.01095
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:bcc-a2
tdb: tdb:FeTe-18Arv.tdb:BCC_A2, tdb:FeTe-19Arv.tdb:BCC_A2

TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: BCC_A2, type code %B, sha256 3c9d8dd7e2fb4098…

40: PHASE BCC_A2 %B 2 1 3 !
41: CONST BCC_A2 : FE% TE : VA : !

FeTe-19Arv.tdb: BCC_A2, type code %B, sha256 543d8ac5bac45cda…

39: PHASE BCC_A2 %B 2 1 3 !
40: CONST BCC_A2 : FE% TE : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FCC_A1 (Fe–Te)

Id: phase:fe-te:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 1142.21–1702.21 K, x(Te) 0–0.00046
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:fcc-a1
tdb: tdb:FeTe-18Arv.tdb:FCC_A1, tdb:FeTe-19Arv.tdb:FCC_A1

TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FCC_A1, type code %A, sha256 3c9d8dd7e2fb4098…

35: PHASE FCC_A1 %A 2 1 1 !
36: CONST FCC_A1 : FE% TE : VA : !

FeTe-19Arv.tdb: FCC_A1, type code %A, sha256 543d8ac5bac45cda…

34: PHASE FCC_A1 %A 2 1 1 !
35: CONST FCC_A1 : FE% TE : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FETE_BETA_HT (Fe–Te)

Id: phase:fe-te:fete-beta; status needs_review
No structure assigned. Why: assessment_declared_compound_differs_from_site_ratios; no_structure_token; off_stoichiometric_model
Candidate (sgte_mmc2): (Fe,Ni)2.53Te2 · hR5 · R3m (160) — Hallstedt 2025 mmc2 row for FETE_BETA_HT: Fe5Te4 (beta-prime)
Candidate (tdb_comment): (FeNi)2.53Te2 · hR5 · R3m — FeTe-18Arv.tdb: 'Prototype (FeNi)2.53Te2 (hR5, R3m), beta-prime'
Candidate (tdb_comment): (FeNi)2.53Te2 · hR5 · R3m — FeTe-19Arv.tdb: 'Prototype (FeNi)2.53Te2 (hR5, R3m), beta-prime'
Stability: stable in 2 of 2 calculated diagram(s): 1072.24–1185.14 K, x(Te) 0.461–0.48909
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:fe-te:fete-beta, corpus:phase:fe-te:fete-beta-ht
tdb: tdb:FeTe-18Arv.tdb:FETE_BETA_HT, tdb:FeTe-19Arv.tdb:FETE_BETA_HT

TDB models of FETE_BETA_HT (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FETE_BETA_HT, type code %, sha256 3c9d8dd7e2fb4098…

62: PHASE FETE_BETA_HT % 2 3 2 !
63: CONST FETE_BETA_HT : FE VA : TE : !

FeTe-19Arv.tdb: FETE_BETA_HT, type code %, sha256 543d8ac5bac45cda…

61: PHASE FETE_BETA_HT % 2 3 2 !
62: CONST FETE_BETA_HT : FE VA : TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FETE_C38 (Fe–Te)

Id: phase:fe-te:fete-c38; status assigned
Structure: Cu2Sb · C38 · tP6 · P4/nmm (129); type st:c38-cu2sb-tp6; tier A: standard phase name; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 300–1117.04 K, x(Te) 0.44834–0.49076
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:fete-c38
tdb: tdb:FeTe-18Arv.tdb:FETE_C38, tdb:FeTe-19Arv.tdb:FETE_C38

TDB models of FETE_C38 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FETE_C38, type code %, sha256 3c9d8dd7e2fb4098…

57: PHASE FETE_C38 % 3 1 1 1 !
58: CONST FETE_C38 : FE : TE : FE VA : !

FeTe-19Arv.tdb: FETE_C38, type code %, sha256 543d8ac5bac45cda…

56: PHASE FETE_C38 % 3 1 1 1 !
57: CONST FETE_C38 : FE : TE : FE VA : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FETE_DELTA (Fe–Te)

Id: phase:fe-te:fete-delta; status needs_review
No structure assigned. Why: no_structure_token; off_stoichiometric_model; sgte_mmc2_rows_disagree
Candidate (sgte_mmc2): CdI2 · C6 · hP3 · P-3m1 (164) — Hallstedt 2025 mmc2 row for FETE_DELTA: Fe2Te3 (delta-prime)
Candidate (sgte_mmc2): (Fe3Te4) · mC14 — Hallstedt 2025 mmc2 row for FETE_DELTA: Fe3Te4 (delta)
Candidate (tdb_comment): CdI2 · hP3 · P-3m1 — FeTe-18Arv.tdb: 'Prototype CdI2 (hP3, P-3m1), delta-prime (cirka Fe2Te3)'
Candidate (tdb_comment): CdI2 · hP3 · P-3m1 — FeTe-19Arv.tdb: 'Prototype CdI2 (hP3, P-3m1), delta-prime (cirka Fe2Te3)'
Stability: stable in 2 of 2 calculated diagram(s): 788.46–1084.69 K, x(Te) 0.55292–0.65624
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:fete-delta
tdb: tdb:FeTe-18Arv.tdb:FETE_DELTA, tdb:FeTe-19Arv.tdb:FETE_DELTA

TDB models of FETE_DELTA (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FETE_DELTA, type code %, sha256 3c9d8dd7e2fb4098…

73: PHASE FETE_DELTA % 3 1 1 2 !
74: CONST FETE_DELTA : FE VA : FE VA : TE : !

FeTe-19Arv.tdb: FETE_DELTA, type code %, sha256 543d8ac5bac45cda…

72: PHASE FETE_DELTA % 3 1 1 2 !
73: CONST FETE_DELTA : FE VA : FE VA : TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FETE_GAMMA (Fe–Te)

Id: phase:fe-te:fete-gamma; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (sgte_mmc2): (FeTe) — Hallstedt 2025 mmc2 row for FETE_GAMMA: FeTe (gamma)
Stoichiometry: Fe 0.4581, Te 0.5419
Stability: stable in 2 of 2 calculated diagram(s): 909.74–1080.24 K, x(Te) 0.54191–0.54191
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:fete-gamma
tdb: tdb:FeTe-18Arv.tdb:FETE_GAMMA, tdb:FeTe-19Arv.tdb:FETE_GAMMA

TDB models of FETE_GAMMA (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FETE_GAMMA, type code %, sha256 3c9d8dd7e2fb4098…

67: PHASE FETE_GAMMA % 2 1 1.183 !
68: CONST FETE_GAMMA : FE : TE : !

FeTe-19Arv.tdb: FETE_GAMMA, type code %, sha256 543d8ac5bac45cda…

66: PHASE FETE_GAMMA % 2 1 1.183 !
67: CONST FETE_GAMMA : FE : TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

FETE2_C18 (Fe–Te)

Id: phase:fe-te:fete2-c18; status assigned
Structure: alpha-FeS2 · C18 · oP6 · Pnnm (58); type st:c18-alpha-fes2-op6; tier A: standard phase name; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 300–925.49 K, x(Te) 0.66667–0.68192
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:fete2-c18
tdb: tdb:FeTe-18Arv.tdb:FETE2_C18, tdb:FeTe-19Arv.tdb:FETE2_C18

TDB models of FETE2_C18 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: FETE2_C18, type code %, sha256 3c9d8dd7e2fb4098…

78: PHASE FETE2_C18 % 2 1 2 !
79: CONST FETE2_C18 : FE VA : TE : !

FeTe-19Arv.tdb: FETE2_C18, type code %, sha256 543d8ac5bac45cda…

77: PHASE FETE2_C18 % 2 1 2 !
78: CONST FETE2_C18 : FE VA : TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

HCP_A3 (Fe–Te)

Id: phase:fe-te:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stoichiometry: Fe 1.0000
Stability: not stable in 2 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-te:hcp-a3
tdb: tdb:FeTe-18Arv.tdb:HCP_A3, tdb:FeTe-19Arv.tdb:HCP_A3

TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: HCP_A3, type code %A, sha256 3c9d8dd7e2fb4098…

45: PHASE HCP_A3 %A 2 1 0.5 !
46: CONST HCP_A3 : FE : VA : !

FeTe-19Arv.tdb: HCP_A3, type code %A, sha256 543d8ac5bac45cda…

44: PHASE HCP_A3 %A 2 1 0.5 !
45: CONST HCP_A3 : FE : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models this phase

ION (Fe–Te)

Id: phase:fe-te:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 720.08–2500 K, x(Te) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:fe-te:ion, corpus:phase:fe-te:liquid
tdb: tdb:FeTe-18Arv.tdb:ION, tdb:FeTe-19Arv.tdb:ION

TDB models of ION (2): PHASE and CONSTITUENT statements as written

FeTe-18Arv.tdb: ION, type code %, sha256 3c9d8dd7e2fb4098…

30: PHASE ION:Y % 2 1 1 !
31: CONST ION:Y : FE+2 : TE-2 VA TE : !

FeTe-19Arv.tdb: ION, type code %, sha256 543d8ac5bac45cda…

29: PHASE ION:Y % 2 1 1 !
30: CONST ION:Y : FE+2 : TE-2 VA TE : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2019.101672 C.-M. Arvhult, C. Gueneau, S. Gosse, M. Selleby, Calphad, 67, 101672(2019).
assessment that models this phase
doi:10.1016/j.jallcom.2018.07.051 C.-M. Arvhult, C. Guéneau, S. Gossé, M. Selleby, Thermodynamic assessment of the Fe-Te system. Part II: Thermodynamic modeling, Journal of Alloys and Compounds 767, 883-893 (2018).
assessment that models 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}
}