Orbital Hybridization Around the Fermi Level Accelerates Momentary Electric Dipoles in LaCrO₃-Based Perovskite for Enhanced Electromagnetic Shielding

LaCrO₃ perovskite, with excellent oxidation stability and adjustable energy band structure, exhibits profound potential as electromagnetic shielding materials in high-temperature, while the low dielectric loss restricts its application. Here, a novel strategy that promoting orbital hybridization around the Fermi level is proposed to induce localized electric dipoles and enhance dielectric loss. The transition metal-oxygen bond transforms from ionic to weakly metallic after substituting low-valence Ni²⁺ for half of the Cr³⁺, then the enhanced orbital hybridization between O-2p and Cr-3d facilitates electron cloud distortion severely and forms a momentary dipole moment, as evidenced by Born effective charges deviating from the nominal valence by four to six-fold. As a result, La(Cr_0.5Ni_0.5)O₃ demonstrates a giant dielectric loss of ≈180, with polarization relaxation contributing 70–80%. Notably, even after heat treatment at 1000 °C for 20 h, the material maintains exceptional shielding effectiveness of 31 dB. This orbital hybridization strategy promoting electric polarization provides an effective approach to enhance dielectric loss about high-temperature resistant perovskites, offering valuable guidance for optimizing their shielding performance.