Elucidating Electrical Instability Mechanism in LaCrO ₃ at High Temperatures: Integrating DFMD Simulations and Experimental Validation

This study systematically elucidates the mechanism underlying high-temperature electrical instability in perovskite-type LaCrO3 by integrating density functional theory-based molecular dynamics simulations with in situ high-temperature X-ray diffraction and high-resolution transmission electron microscopy. Our findings reveal localized lattice disorder, rather than the previously proposed oxidation mechanism driven by Cr3+–oxygen interactions, as the intrinsic driver of electrical instability. Prolonged exposure to elevated temperatures induces severe lattice distortion and eventual bond cleavage in these disordered regions, leading to a continuous decline in electrical performance. Importantly, this mechanism is demonstrated to be universally applicable across perovskite chromate systems, offering critical theoretical guidance for the design of high-temperature materials with exceptional electrical stability.