Entropy-enabled electronic-state diversification to boost electromagnetic shielding of perovskite oxides with excellent thermal stability

Conventional perovskite oxides access only a narrow subset of transition-metal electronic configurations, inherently restricting their transport functionality. Here, we show that high-entropy engineering unlocks this hidden electronic-state space in ABO₃-type perovskites by introducing multiple principal transition-metal cations at the B site. The resulting configurational entropy facilitates multivalent states and amplifies inter-electron interactions, giving rise to pronounced electronic-state splitting near the Fermi level and a markedly reduced transport barrier. This entropy-enabled electronic diversification dramatically enhances electron hopping across heterogeneous transition-metal centers, driving a continuous evolution from insulating to highly conductive behavior, which accounts for enhanced electromagnetic shielding effectiveness. As a representative case, high-entropy La(CrMnNiCoCu)O₃ exhibits more than a threefold increase in carrier mobility and an order-of-magnitude enhancement in carrier concentration compared to LaCrO₃, with resistivity reduced exponentially to 1.94 Ω·cm. Owing to the entropy-enabled electronic landscape and robust perovskite framework, the material achieves electromagnetic shielding effectiveness exceeding 27 dB (over the X band) at a thickness of 0.8 mm and retains stable performance after repeated heat treatments at 1000 °C. This work establishes entropy-enabled electronic-state diversification as a fundamentally new paradigm for designing electrically functional perovskite oxides for electromagnetic protection in harsh environment.