X-ray and magnetic studies of scandium substituted Ni-Zn ferrites

Abstract

The approach of simultaneous substitutions by aiming at a systematic dilution of both of the sublattices to obtain the highest possible magnetization in a given system has been made use of, since this parameter is highly desirable in the fabrication of core materials for switched mode power supplies (SMPS), Ferrite series of the compositions Ni/sub 0.65/Zn/sub 0.35/Fe/sub 2-x/ScO/sub 4/, with x values ranging from 0.00 to 0.25 in steps of 0.05, and Ni/sub 0.65-x/Zn/sub 0.35+x/Fe/sub 2-x/Sc/sub x/O/sub 4/, with x values ranging from 0.000-0.125 in steps of 0.025, have been prepared using optimum sintering conditions for this study. Observed variations in saturation magnetization and Curie temperature for the two series have been explained on the basis of site distributions of the Zn/sup 2+/ and Sc/sup 3+/ ions and the strength of the exchange interactions between magnetic ions. From the magnetization studies, conclusions have been drawn toward the cation distribution in the ferrites, Variations of lattice constant with the substituent concentration in both of the systems are also discussed.