SYNTHESIS AND CHARACTERIZATION OF Ni-Mn SUBSTITUTED CaFe12019 NANOPARTICLES BY SOL-GEL METHOD

Abstract

Calcium hexaferrite with Ni-Mn (i.e CaNio,sMno.5Fe11O19) doped particles were prepared by using sol-gel technique. The precipitate was calcinated at 8000C,9000C,10000C and 1100°C for 4 hours and characterized by using various instrumental techniques. The structural studies of the samples were studied by using XRD and FESEM. The field dependent magnetic properties of prepared Ni-Mn substituted Calcium hexaferrite nanoparticles powder were investigated at room temperature by using vibrating sample magnetometer device and Dielectric study is done by using HIOKI3522-50/3532-50 LCR Meter. It has been observed that the type of dopant plays a crucial role in deciding the morphology of the particles. There is significant change in crystallite size of the resultant Calcium hexaferrite in sol-gel technique. Magnetic study reveals that the value of anisotropy constant (K) depends on the type of surfactant used. The effect of sintering temperature on the properties of CaFe12O19 hexaferrites with Ni-Mn doped particles has been studied. The value of saturation magnetization(Ms) depends on types of surfactant used. Suitable ferrite components are designed for use in systems, like radar, satellite uplinks, industrial heaters or dryers and nuclear systems which employ high power microwaves. Ferrites are also used as microwave absorbers. Radar absorbing paint made from ferrites can be used to coat military aircraft for stealth operation. In this study, some hexaferrites have been synthesized and characterized for their possible use at high frequencies. Three series of M type hexagonal ferrites having the general formula McFe12O19 in which Me was Bat' ,Sr2+ or Cat+ and Fe3+ ions were replaced partly by Ni-Mn ions were chosen for synthesis and study.