Manufacture of Zn-Co Substituted Y-Type Barium Hexagonal Ferrites by Citrate Precursor Route and Their Microwave Properties

摘要

Ba_2Zn_xCo_(2-x)Fe_(12)O_(22) hexaferrites with x =0.0, 0.4, 0.8, 1.2, 1.6 and 2.0 were prepared by citrate sol-gel process. The complex dielectric constant and complex permeability of hexaferrites were studied as functions of the measuring frequency, composition and sintering temperature in the range 100 MHz approx 6 GHz. The natural resonance phenomenon is observed in mu" spectrum for all Y-type hexaferrites, which resonance frequency is dependent on zinc content and firing temperature. The natural resonance frequencies of Co_2Y hexaferrite were calculated, which is in agreement with the measuring results. The reflection loss of those ferrites is measuring frequency as well as absorber thickness dependent, and the higher the frequency and the thickness are, the higher the reflection loss is.