Microwave sintering of (Bi 0.75Ca 1.2Y 1.05)(V 0.6Fe 4.4)O 12 microwave magnetic materials

Abstract

Microwave sintering (ms) process is applied to efficiently densify the (Bi 0.75Ca 1.2Y 1.05)(V 0.6Fe 4.4)O 12, Bi-CVG, materials, without inducing a deleterious effect on their microwave magnetic properties. A microwave sintering process can sinter the Bi-CVG materials to a density as high as 96.5%T. D., by firing the samples at 1030 °C (30 min). In contrast, it needs 1060 °C (6 h) to densify the materials to the same high density by a conventional sintering (cs) process. The ms-processed Bi-CVG materials possess pronouncedly smaller grain size (∼1.2 μm), which markedly hinders their low frequency magnetization process (in a few tens of MHz frequency regime), resulting in larger coercive field ( Hc) and smaller initial permeability ( μ i), as compared with the cs-processed large grain samples. But such a small grain characteristic insignificantly degrades the microwave magnetic properties, the resonance line width (Δ H), of the Bi-CVG materials.