Fe–Pu 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–Pu system page · Markdown · field reference

Phases of the Fe–Pu system (10)
Phase	Structure	Basis	Stability (calculated)	TDB models
TETRAGONAL_A6 phase:fe-pu:a6-tetragonal	In · A6 · tI2 · I4/mmm (139)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 617.4–907.61 K, x(Pu) 1–1	2
BCC_A2 phase:fe-pu:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–3999.25 K, x(Pu) 0–1	2
FCC_A1 phase:fe-pu:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 581.18–1690.33 K, x(Pu) 0–1	2
FE2PU_C15 phase:fe-pu:fe2pu-c15	Cu2Mg · C15 · cF24 · Fd-3m (227)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1512.98 K, x(Pu) 0.32714–0.33375	2
FEPU6_D2C phase:fe-pu:fepu6-d2c	MnU6 · D2_c · tI28 · I4/mcm (140)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–700.61 K, x(Pu) 0.85276–0.85714	2
HCP_A3 phase:fe-pu:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 2 calculated diagram(s)	2
LIQUID phase:fe-pu:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 666.74–4000 K, x(Pu) 0–1	2
ALPHA_PU phase:fe-pu:pu-alpha		needs_review	stable in 2 of 2 calculated diagram(s): 300–397.62 K, x(Pu) 1–1	2
BETA_PU phase:fe-pu:pu-beta		needs_review	stable in 2 of 2 calculated diagram(s): 397.62–487.9 K, x(Pu) 1–1	2
GAMMA_PU phase:fe-pu:pu-gamma		needs_review	stable in 2 of 2 calculated diagram(s): 487.9–607.92 K, x(Pu) 1–1	2

TETRAGONAL_A6 (Fe–Pu)

Id: phase:fe-pu:a6-tetragonal; status assigned
Structure: In · A6 · tI2 · I4/mmm (139); type st:a6-in-ti2; tier A: standard phase name; confidence high
Stoichiometry: Pu 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 617.4–907.61 K, x(Pu) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:a6-tetragonal
tdb: tdb:FePu-01Kur.tdb:TETRAGONAL_A6, tdb:FePu-04Tur.tdb:TETRAGONAL_A6

TDB models of TETRAGONAL_A6 (2): PHASE and CONSTITUENT statements as written

FePu-01Kur.tdb: TETRAGONAL_A6, type code %, sha256 a1185b9017b19c8f…

41: PHASE TETRAGONAL_A6 % 1 1 !
42: CONST TETRAGONAL_A6 : PU : !

FePu-04Tur.tdb: TETRAGONAL_A6, type code %, sha256 212316a67a63edf4…

40: PHASE TETRAGONAL_A6 % 1 1 !
41: CONST TETRAGONAL_A6 : PU : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

BCC_A2 (Fe–Pu)

Id: phase:fe-pu: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): 300–3999.25 K, x(Pu) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:bcc-a2
tdb: tdb:FePu-01Kur.tdb:BCC_A2, tdb:FePu-04Tur.tdb:BCC_A2

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

FePu-01Kur.tdb: BCC_A2, type code %B, sha256 a1185b9017b19c8f…

31: PHASE BCC_A2 %B 2 1 3 !
32: CONST BCC_A2 : FE% PU% : VA : !

FePu-04Tur.tdb: BCC_A2, type code %B, sha256 212316a67a63edf4…

30: PHASE BCC_A2 %B 2 1 3 !
31: CONST BCC_A2 : FE% PU% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

FCC_A1 (Fe–Pu)

Id: phase:fe-pu: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): 581.18–1690.33 K, x(Pu) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:fcc-a1
tdb: tdb:FePu-01Kur.tdb:FCC_A1, tdb:FePu-04Tur.tdb:FCC_A1

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

FePu-01Kur.tdb: FCC_A1, type code %A, sha256 a1185b9017b19c8f…

26: PHASE FCC_A1 %A 2 1 1 !
27: CONST FCC_A1 : FE% PU : VA : !

FePu-04Tur.tdb: FCC_A1, type code %A, sha256 212316a67a63edf4…

25: PHASE FCC_A1 %A 2 1 1 !
26: CONST FCC_A1 : FE% PU : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

FE2PU_C15 (Fe–Pu)

Id: phase:fe-pu:fe2pu-c15; 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 FePu-04Tur.tdb also describes the disordered state
Stability: stable in 2 of 2 calculated diagram(s): 300–1512.98 K, x(Pu) 0.32714–0.33375
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:fe2pu-c15
tdb: tdb:FePu-01Kur.tdb:FE2PU_C15, tdb:FePu-04Tur.tdb:FE2PU_C15

TDB models of FE2PU_C15 (2): PHASE and CONSTITUENT statements as written

FePu-01Kur.tdb: FE2PU_C15, type code %, sha256 a1185b9017b19c8f…

61: PHASE FE2PU_C15 % 2 2 1 !
62: CONST FE2PU_C15 : FE : PU : !

FePu-04Tur.tdb: FE2PU_C15, type code %, sha256 212316a67a63edf4…

60: PHASE FE2PU_C15 % 2 2 1 !
61: CONST FE2PU_C15 : FE% PU : FE PU% : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

FEPU6_D2C (Fe–Pu)

Id: phase:fe-pu:fepu6-d2c; status assigned
Structure: MnU6 · D2_c · tI28 · I4/mcm (140); type st:d2-c-mnu6-ti28; tier A: standard phase name; confidence high
Caveat: partitioned order/disorder model in FePu-04Tur.tdb also describes the disordered state
Stability: stable in 2 of 2 calculated diagram(s): 300–700.61 K, x(Pu) 0.85276–0.85714
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:fepu6-d2c
tdb: tdb:FePu-01Kur.tdb:FEPU6_D2C, tdb:FePu-04Tur.tdb:FEPU6_D2C

TDB models of FEPU6_D2C (2): PHASE and CONSTITUENT statements as written

FePu-01Kur.tdb: FEPU6_D2C, type code %, sha256 a1185b9017b19c8f…

66: PHASE FEPU6_D2C % 2 1 6 !
67: CONST FEPU6_D2C : FE : PU : !

FePu-04Tur.tdb: FEPU6_D2C, type code %, sha256 212316a67a63edf4…

65: PHASE FEPU6_D2C % 2 1 6 !
66: CONST FEPU6_D2C : FE% PU : FE PU% : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

HCP_A3 (Fe–Pu)

Id: phase:fe-pu: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-pu:hcp-a3
tdb: tdb:FePu-01Kur.tdb:HCP_A3, tdb:FePu-04Tur.tdb:HCP_A3

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

FePu-01Kur.tdb: HCP_A3, type code %A, sha256 a1185b9017b19c8f…

36: PHASE HCP_A3 %A 2 1 0.5 !
37: CONST HCP_A3 : FE : VA : !

FePu-04Tur.tdb: HCP_A3, type code %A, sha256 212316a67a63edf4…

35: PHASE HCP_A3 %A 2 1 0.5 !
36: CONST HCP_A3 : FE : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

LIQUID (Fe–Pu)

Id: phase:fe-pu:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 666.74–4000 K, x(Pu) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:liquid
tdb: tdb:FePu-01Kur.tdb:LIQUID, tdb:FePu-04Tur.tdb:LIQUID

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

FePu-01Kur.tdb: LIQUID, type code %, sha256 a1185b9017b19c8f…

21: PHASE LIQUID:L % 1 1 !
22: CONST LIQUID:L : FE PU : !

FePu-04Tur.tdb: LIQUID, type code %, sha256 212316a67a63edf4…

20: PHASE LIQUID:L % 1 1 !
21: CONST LIQUID:L : FE PU : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

ALPHA_PU (Fe–Pu)

Id: phase:fe-pu:pu-alpha; status needs_review
No structure assigned. Why: no_structure_token; unary_composition
Candidate (sgte_mmc2): alpha-Pu · mP16 · P2_1/m (11) — Hallstedt 2025 mmc2 row for ALPHA_PU: Pu (alpha)
Candidate (tdb_comment): alpha-Pu · mP16 · P2_1/m — FePu-01Kur.tdb: 'Prototype alpha-Pu (mP16, P2_1/m)'
Candidate (tdb_comment): alpha-Pu · mP16 · P2_1/m — FePu-04Tur.tdb: 'Prototype alpha-Pu (mP16, P2_1/m)'
Stoichiometry: Pu 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 300–397.62 K, x(Pu) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:pu-alpha
tdb: tdb:FePu-01Kur.tdb:ALPHA_PU, tdb:FePu-04Tur.tdb:ALPHA_PU

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

FePu-01Kur.tdb: ALPHA_PU, type code %, sha256 a1185b9017b19c8f…

46: PHASE ALPHA_PU % 1 1 !
47: CONST ALPHA_PU : PU : !

FePu-04Tur.tdb: ALPHA_PU, type code %, sha256 212316a67a63edf4…

45: PHASE ALPHA_PU % 1 1 !
46: CONST ALPHA_PU : PU : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

BETA_PU (Fe–Pu)

Id: phase:fe-pu:pu-beta; status needs_review
No structure assigned. Why: no_structure_token; unary_composition
Candidate (sgte_mmc2): beta-Pu · mC34 · C2/m (12) — Hallstedt 2025 mmc2 row for BETA_PU: Pu (beta)
Candidate (tdb_comment): beta-Pu · mC34 · C2/m — FePu-01Kur.tdb: 'Prototype beta-Pu (mC34, C2/m)'
Candidate (tdb_comment): beta-Pu · mC34 · C2/m — FePu-04Tur.tdb: 'Prototype beta-Pu (mC34, C2/m)'
Stoichiometry: Pu 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 397.62–487.9 K, x(Pu) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:pu-beta
tdb: tdb:FePu-01Kur.tdb:BETA_PU, tdb:FePu-04Tur.tdb:BETA_PU

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

FePu-01Kur.tdb: BETA_PU, type code %, sha256 a1185b9017b19c8f…

51: PHASE BETA_PU % 1 1 !
52: CONST BETA_PU : PU : !

FePu-04Tur.tdb: BETA_PU, type code %, sha256 212316a67a63edf4…

50: PHASE BETA_PU % 1 1 !
51: CONST BETA_PU : PU : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
assessment that models this phase

GAMMA_PU (Fe–Pu)

Id: phase:fe-pu:pu-gamma; status needs_review
No structure assigned. Why: no_structure_token; unary_composition
Candidate (sgte_mmc2): gamma-Pu · oF8 · Fddd (70) — Hallstedt 2025 mmc2 row for GAMMA_PU: Hg4In, Pu (gamma)
Candidate (tdb_comment): gamma-Pu · oF8 · Fddd — FePu-01Kur.tdb: 'Prototype gamma-Pu (oF8, Fddd)'
Candidate (tdb_comment): gamma-Pu · oF8 · Fddd — FePu-04Tur.tdb: 'Prototype gamma-Pu (oF8, Fddd)'
Stoichiometry: Pu 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 487.9–607.92 K, x(Pu) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:fe-pu:pu-gamma
tdb: tdb:FePu-01Kur.tdb:GAMMA_PU, tdb:FePu-04Tur.tdb:GAMMA_PU

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

FePu-01Kur.tdb: GAMMA_PU, type code %, sha256 a1185b9017b19c8f…

56: PHASE GAMMA_PU % 1 1 !
57: CONST GAMMA_PU : PU : !

FePu-04Tur.tdb: GAMMA_PU, type code %, sha256 212316a67a63edf4…

55: PHASE GAMMA_PU % 1 1 !
56: CONST GAMMA_PU : PU : !

Example references (1 of 1; assessments first):

doi:10.1016/S0022-3115(01)00473-1 M. Kurata, K. Nakamura, T. Ogata, J. Nucl. Mater., 294, 123-29(2001).
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}
}