All samples were prepared using conventional solid state reaction technique and were sintered at two different temperatures in air for 1 hour. Structural and surface morphology were studied by x-ray diffraction (XRD) method and high resolution optical microscopy respectively. The magnetic properties of these ferrites were characterized by frequency (1 kHz-13MHz) and temperature dependence complex permeability measurements. DC magnetizations of all samples were measured using the Superconducting Quantum Interface Device (SQUID) magnetometer. The XRD patterns of all samples have clearly indicated the formation of spinel structure. The change in lattice parameter can be explained on the basis of the ionic radii. Resonance frequency and Neel temperature decreased as Zn content increased. Possible explanations for the observed characteristics of microstructures, initial permeability, DC magnetization, and Neel temperature of the studied samples have been discussed. Это и многое другое вы найдете в книге Frequency dependence permeability of ferrites (Brajalal Sinha)