High Frequency Mn-Zn Power Ferrites

Relationships between chemical composition, microstructure and core losses of Mn-Zn power ferrites are discussed. We report in this paper the influence on core losses of silica-calcia additions and Ti-substitutions for optimising a power ferrite from 25 kHz up to 2 MHz. Our results are well explained using core losses description including the domain walls resonance-relaxation loss contribution depicted in previous papers and confirm that it is essential to take this contribution into account when optimising low losses ferrites in specific conditions of temperature, frequency and induction, especially in a high frequency range.