Understanding the microwave heating properties of La–Ce–Ni oxides based on structural, dielectric, and conductive analysis

Microwaves can selectively and rapidly heat materials upon absorption, offering advantages over conventional heating methods. However, practical applications in oxide materials remain limited due to insufficient understanding of fundamental heating mechanisms and inadequate control of heating characteristics. In this study, we elucidated the heating mechanism of La-Ce-Ni oxides to develop oxide materials with excellent microwave heating properties. We comprehensively investigated the crystal structure, microstructure, electrical conductivity, and dielectric properties of La-Ce-Ni oxides with various compositions. In La-Ce-Ni oxides, the strong CeO₂-LaNiO₃ interaction induced structural distortions and modified dielectric properties, which predominantly contributed the heating properties under a microwave electric field, rather than electrical conductivity. The dielectric properties, rather than the electrical conductivity, were the primary factors determining the microwave heating performance of this system.