Study on microwave absorbing properties of Mn-Zn ferrites prepared by sol-gel/combustion method

Mn-Zn ferrite Mn0.3Zn0.7Fe2O4 was prepared by sol-gel/combustion process, and the preparation conditions were investigated. The samples were characterized by XRD, SEM, TG-DSC, Network analyzer, and so on. The results showed that the pure Mn-Zn ferrite with a uniform particle size of about 160 nm could be formed when pH value was around 7.0, the mole ratio of citrate and metal salt was 1:1, the calcining temperature was 1050°C, and the calcining time was 3 h. The as-prepared Mn0.3Zn0.7Fe2O4 ferrite performed both the dielectric loss properties and magnetic loss properties. It showed excellent microwave absorption properties with the reflection loss less than -10 dB in the frequency range of 12.5-15 GHz.