Unusual Strain Relaxation and Dirac Semimetallic Behavior in Epitaxial Antiperovskite Nitrides

ABSTRACT Antiperovskite nitrides (X 3 AN) serve as both structural and conceptual counterparts to the extensively studied perovskite oxides. However, their epitaxial stabilization and the associated emergent electronic properties remain largely unexplored. Here, we report the successful growth of Ni 3 InN thin films on perovskite substrates with lattice constants ranging from 3.78 to 3.98 Å. First‐principles phonon calculations confirm the dynamical stability of cubic phase Ni 3 InN, providing the basis for epitaxial synthesis. High‐resolution scanning transmission electron microscopy reveals (001)‐oriented coherent interfaces when Ni 3 InN is grown on LaAlO 3 and SrTiO 3 , while the growth on DyScO 3 results in an unexpected (011)‐oriented interface, consistent with surface‐energy calculations. Transport measurements highlight a strain‐controlled within a Fermi‐liquid behavior, which correlates with variations in Ni‐3 d bandwidth, Ni‐3 d /N‐2 p hybridization. Band structure calculations reveal a unique dual contribution near the Fermi level: a Dirac‐like dispersion that supports high mobility and a Ni‐3 d ‐derived manifold that governs strange‐metal transport, exhibiting a reduced slope compared to oxide perovskites. Notably, the formal Ni valence (∼+2/3) places Ni 3 InN within an overdoped correlated‐metal regime, distinguishing it from most oxide perovskites. This positions antiperovskite nitrides as a promising platform for investigating overdoped Fermi liquids and strange‐metal behavior.