High-entropy perovskite (Y0.2La0.2Sm0.2Nd0.2Gd0.2)CoO3 with dielectric-conductive synergy achieving wide-temperature-range EMI shielding and electromagnetic wave absorption compatibility

Traditional EMI shielding materials encounter significant problems, including pyrolytic deformation, oxidation and reduced performance at high temperatures. Perovskite oxide ceramics, with non-oxidizing properties and increasing conductivity with rising temperature, offer solutions. To address these issues, high-entropy perovskite cobaltate ceramics (Y 0.2 La 0.2 Sm 0.2 Nd 0.2 Gd 0.2 )CoO 3 (HE RECoO 3 ) were designed and synthesized via a straightforward one-step solid-state reaction. These ceramics exhibit unique transport properties due to the high-entropy effect, multivalent Co ions, and high defect concentration. The resulting dielectric-conductive synergy enables microwave absorption and wide-temperature-range EMI shielding compatibility, alongside thermoelectric conversion capabilities. Specifically, treating HE RECoO 3 at 1200 °C for 2 h shows a reflection loss of up to −62.60 dB at 25 °C and SE values >30 dB across the entire X-band at 500 °C, and a Seebeck coefficient of 53.56 μV/K. This simple, cost-effective synthesis process makes HE RECoO 3 ideal for wide-temperature-range EMI shielding applications.