Dependence of magnetic and microwave loss on evolving microstructure in yttrium iron garnet

摘要: The parallel magnetic and microwave loss dependence on microstructural evolutions in several polycrystalline yttrium iron garnet samples were studied detail, focusing the attendant occurrence of their relationships. In this study, YIG synthesized by employing mechanical alloying technique sintering toroidal compacts at temperatures from 600 to 1400 °C. characterized for evolution crystalline phases, structure, microstructure, hysteresis parameters, losses electrical resistivity. results showed an increasing tendency saturation magnetization with grain size, which is attributed crystallinity increase grains. M–H loop a transition disordered-to-ordered magnetism belongs different magnetically dominant stages formation. starting appearance room temperature ferromagnetic order suggested sigmoid-shaped loops seems be dependent crystallinity, phase purity sufficient number large enough domain-containing grains having been formed microstructure. An trend transmission size may increment contribution domain wall resonance samples. changes associated processes relaxation due movements damping spin rotation contributes variations linewidth increased resistivity while microstructure was evolving believed strongly indicates improved compositional stoichiometry.