Dissolution-Segregation Behavior of Ca during the Sintering Process of MnZn Ferrite

Abstract

Dissolution and segregation behavior of Ca in the Sintering process of MnZn ferrite were investigated by microstructure analysis. It was revealed that, as the temperature rises to above 1000°C, Ca dissolves to the spinel lattice and disperses uniformly in the ferrite at the soaking step. Ca begins to segregate to the grain boundaries in the slow cooling process, and the segregation proceeds below 1100°C rather than above. This suggests that control of the cooling in this temperature range is of great importance for the formation of high-resistivity grain boundaries and the lowering of core loss.