Study of Structural, electrical and magnetic properties of Al~(3+) ions doped Mg_(0.2)Mn_(0.5)Ni_(0.3)AlyFe_(2-y)O_4 spinel ferrites for high frequency applications

摘要

Structural, electrical and bulk magnetic properties of spinel system Mg_(0.2)Mn_(0.5)Ni_(0.3)Al_yFe_(2-y)O_4 with y varying from 0.0-0.3 in step of 0.1, synthesized by citrate precursor technique at 1200?°C, have been investigated. Variations of initial permeability, and RLF (relative loss factor) with frequency, in range of 0.075-20 MHz at different temperatures have been studied. Initial permeability (μ_i) attains very high value i.e. 59487 and RLF has very low values of 10~(-6)-10~(-5) which is three orders of magnitude less than the samples prepared by conventional method. There is significant reduction in initial permeability, Curie temperature, RLF and dielectric loss with Al~(3+) ions. Therefore, very high μ_i and very low values of RLF and dielectric loss are attributed to better compositional stoichiometery and uniform microstructure, making these ferrites attractive for use in high frequency applications.