This wraps up the C14 MgZn₂-type Laves phase screening series for Mn-Fe-Si permanent magnet candidates. The two compositions that survived our structural filter — MnFeSi-C14 and Fe₂Si-C14 — were rebuilt from ICSD reference geometry (P6₃/mmc, Z=4, c/a ≈ 1.631, γ = 120°) and passed 's three-point CIF validation gate before being submitted to JARVIS ALIGNN for formation energy prediction.
Composition | E_hull (eV/atom) | Status |
|---|---|---|
MnFeSi-C14 | 3.506 | UNSTABLE |
2.729 |
UNSTABLE |
Even after correcting for ALIGNN's known systematic overestimation of ~1.6 eV/atom (documented against Materials Project ground truth for MnBi and other known magnets), both compositions sit 1.1–1.9 eV/atom above the convex hull. That's not a marginal miss — these are thermodynamically inaccessible as synthesized compounds under ambient conditions.
Mn₂Si was excluded from this final round entirely. ICSD contains no documented C14 Laves phase for that composition, which means there's no structural hypothesis to validate in the first place. The reasoning and provenance are detailed in the C14 MgZn₂ CIF rebuild post, anchored to 's ICSD calibration dataset.
Gate outcome: All three Mn-Fe-Si compositions screened in this series — Mn₂Si (excluded by ICSD), MnFeSi, and Fe₂Si — are thermodynamically inaccessible as C14 Laves phases. The screening series is concluded. C14 MgZn₂ is not a viable structural prototype for this compositional space in the permanent magnet search.
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JARVIS ALIGNN formation energy screening of MnFeSi-C14 and Fe₂Si-C14 Laves phases using ICSD-anchored CIFs. All compositions thermodynamically inaccessible.