Improvement in the Dielectric Properties of Barium Hexaferrite Nanoparticles by Substitution of Zinc and Nickel

Abstract

There has been a tremendous interest in hexagonal ferrites during the last ten years for a number of marvelous applications. Particularly they find their use in electronic industry for wireless communications such as mobile phones at MW/GHz frequencies, in the absorption of electromagnetic wave, stealth technologies, radar absorbing materials (RAM) and also as composite materials. “Due to their expanded use, hexaferrites have become very important magnetic materials being produced commercially. Barium based M-type hexaferrites, BaM, (BaFe12O19) is one of such materials that is currently used in these applications. In the current work BaM prepared using Zn and Ni dopants to meet the desired target. For this purpose dopants substitution is performed in two series of Ba1-xZnxFe12O19 (x = 0, 0.2, 0.35, 0.5) and Ba1-2xZnxNixFe12O19 (x = 0, 0.1, 0.175, 0.2) using sol gel method. The aqueous solution, containing metal nitrates were brought in use to prepare barium hexferrite nanoparticles. The prepared samples were calcined at 800 °C for 8 hrs. FTIR, XRD and SEM were used for study of structural properties. XRD pattern confirmed the formation of pure M-type hexagonal phase. Range of the particle size of the powder prepared by this method is from 16 nm to 60 nm. IR peaks observed after calcinations also confirmed the metal-oxygen bond bending & stretching vibrations of the desired product. Electrical properties like dielectric constant, dielectric loss factor, dielectric tangent loss and AC conductivity were also measured which were in close agreement to achieve the target.” Dielectric constant for un-doped material was 29 where as it increase gradually after doping with Zinc and Nickel which shows that resistance of the sample has been reduced and its conductivity increases.