EFFECT OF PARTICLE SIZE ON THE PROPERTIES OF Mg–Mn FERRITES

Abstract

Processing of ferrites has gained tremendous importance in recent times in order to meet high performance demands on ferrites in keeping with the fast emerging technologies. The main focus of research in the 21st century is towards the formation of smaller magnetic particles. In normal ceramic methods we cannot control particle size and porosity, whereas in precursor methods we can control both. In the present study we have synthesized Mg 0.9 Mn 0.1 Fe 2 O 4 ferrites by the normal ceramic method and the citrate precursor method. By the citrate method we have simultaneously reduced the particle size and sintering temperature as compared to the normal ceramic method. By the citrate method, direct current (DC) resistivity is increased by two orders of magnitude, and electrical as well as magnetic losses are reduced as compared to the normal ceramic method. The initial permeability is reduced in both citrate method as compared to the normal ceramic methods. However, with sintering temperature the initial permeability increases. The dielectric constant is reduced by the citrate method as compared to normal ceramic methods. These observations are explained on the basis of various mechanisms and models.