Synthesis and Magnetic Properties of Ba2Ni2–xZnxFe12O22

Y-type hexagonal ferrites with the nominal chemical composition Ba2Ni2–xZnxFe12O22 (0.0 ≤ x ≤ 0.6 with a step of 0.1) have been synthesized by the conventional solid state reaction method and sintered in the temperature range 1150 ̊C 1250 ̊C to study their structural and magnetic properties. The aim of the present work is to increase the magnetic properties of Y-type hexaferrites by Zn substitution. X-ray diffraction analysis confirms the formation of the hexagonal phase. The effect of chemical composition on the lattice parameter, density and porosity is studied. The lattice parameter increases with Zn substitution. The density increases with Zn substitution up to a certain level and after that density decreases. The ac magnetic properties of the hexaferrites sintered at temperature 1200 ̊C are characterized within the frequency range 100 kHz 120 MHz. The real part (μi') of the complex initial permeability for different compositions indicates that μi' decreases with increase in frequency. The permeability increases with the increase in Zn content, reaches a maximum value and then decreases with further increase in Zn content. Magnetization has been measured using the Superconducting Quantum Interference Device (SQUID) magnetometer. The saturation magnetization is observed to be maximum at x = 0.1 and then decreases with Zn content for x > 0.1. From the M-H curve it is clear that at room temperature the polycrystalline Ba2Ni2–xZnxFe12O22 compositions are in ferrimagnetic state.