Hf–N phases

8 phases (tier A 2, tier C 2, liquid 1, gas 2, interstitial_fcc_a1_compound 1); 8 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 · Hf–N system page · Markdown · field reference

Phases of the Hf–N system (8)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:hf-n:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 2016.03–3999.75 K, x(N) 0–0	1
FCC_A1 phase:hf-n:fcc-a1	NaCl · B1 · cF8 · Fm-3m (225)	assigned	stable in 1 of 1 calculated diagram(s): 300–3650.81 K, x(N) 0.37756–0.52058	1
GAS phase:hf-n:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300.72–4000 K, x(N) 0.99285–1	1
HCP_A3 phase:hf-n:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–3187.99 K, x(N) 0–0.31441	1
HF3N2 phase:hf-n:hf3n2	TiS-9R · hR6 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2245.01 K, x(N) 0.4–0.4	1
HF4N3 phase:hf-n:hf4n3	Sc2Te3 · hR8 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 353.56–2592.71 K, x(N) 0.42857–0.42857	1
LIQUID phase:hf-n:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 2478.01–4000 K, x(N) 0–0.26474	1
N2GAS phase:hf-n:n2gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300–2185 K, x(N) 1–1	1

BCC_A2 (Hf–N)

Id: phase:hf-n: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 1 of 1 calculated diagram(s): 2016.03–3999.75 K, x(N) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:bcc-a2
tdb: tdb:HfN-18Pan.tdb:BCC_A2

TDB models of BCC_A2 (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: BCC_A2, type code %B, sha256 e62247a157b146a1…

45: PHASE BCC_A2 %B 2 1 3 !
46: CONST BCC_A2 : HF : VA% N : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

FCC_A1 (Hf–N)

Id: phase:hf-n:fcc-a1; status assigned
Structure: NaCl · B1 · cF8 · Fm-3m (225); type st:b1-nacl-cf8; interstitial_fcc_a1_compound; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–3650.81 K, x(N) 0.37756–0.52058
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:fcc-a1
tdb: tdb:HfN-18Pan.tdb:FCC_A1

TDB models of FCC_A1 (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: FCC_A1, type code %A, sha256 e62247a157b146a1…

40: PHASE FCC_A1 %A 2 1 1 !
41: CONST FCC_A1 : HF% VA : VA N% : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

GAS (Hf–N)

Id: phase:hf-n:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300.72–4000 K, x(N) 0.99285–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:gas
tdb: tdb:HfN-18Pan.tdb:GAS

TDB models of GAS (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: GAS, type code %, sha256 e62247a157b146a1…

66: PHASE GAS:G % 1 1 !
67: CONST GAS:G : N N2 N3 HF : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

HCP_A3 (Hf–N)

Id: phase:hf-n: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: stable in 1 of 1 calculated diagram(s): 300–3187.99 K, x(N) 0–0.31441
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:hcp-a3
tdb: tdb:HfN-18Pan.tdb:HCP_A3

TDB models of HCP_A3 (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: HCP_A3, type code %A, sha256 e62247a157b146a1…

50: PHASE HCP_A3 %A 2 1 0.5 !
51: CONST HCP_A3 : HF : VA% N : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

HF3N2 (Hf–N)

Id: phase:hf-n:hf3n2; status assigned
Structure: TiS-9R · hR6 · R-3m (166); type st:tis-9r-hr6; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
Caveat: not certain from the name or DFT alone (dft_space_group_166_matches_3_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Hf 0.6000, N 0.4000
Stability: stable in 1 of 1 calculated diagram(s): 300–2245.01 K, x(N) 0.4–0.4
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:hf3n2
tdb: tdb:HfN-18Pan.tdb:HF3N2

TDB models of HF3N2 (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: HF3N2, type code %, sha256 e62247a157b146a1…

55: PHASE HF3N2 % 2 3 2 !
56: CONST HF3N2 : HF : N : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

HF4N3 (Hf–N)

Id: phase:hf-n:hf4n3; status assigned
Structure: Sc2Te3 · hR8 · R-3m (166); type st:sc2te3-hr8; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Hf 0.5714, N 0.4286
Stability: stable in 1 of 1 calculated diagram(s): 353.56–2592.71 K, x(N) 0.42857–0.42857
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:hf4n3
tdb: tdb:HfN-18Pan.tdb:HF4N3

TDB models of HF4N3 (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: HF4N3, type code %, sha256 e62247a157b146a1…

60: PHASE HF4N3 % 2 4 3 !
61: CONST HF4N3 : HF : N : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

LIQUID (Hf–N)

Id: phase:hf-n:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 2478.01–4000 K, x(N) 0–0.26474
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:liquid
tdb: tdb:HfN-18Pan.tdb:LIQUID

TDB models of LIQUID (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: LIQUID, type code %, sha256 e62247a157b146a1…

35: PHASE LIQUID:L % 1 1 !
36: CONST LIQUID:L : HF N : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(2018).
assessment that models this phase

N2GAS (Hf–N)

Id: phase:hf-n:n2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2185 K, x(N) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-n:n2gas
tdb: tdb:HfN-18Pan.tdb:N2GAS

TDB models of N2GAS (1): PHASE and CONSTITUENT statements as written

HfN-18Pan.tdb: N2GAS, type code %, sha256 e62247a157b146a1…

63: PHASE N2GAS % 1 1 !
64: CONST N2GAS : N2 : !

Example references (1 of 1; assessments first):

doi:10.2298/JMMB170520055P M. Pang, Y. Peng, P. Zhou, Y. Du, J. Mining Metall. B, 54B, 111-18(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}
}