COMPARISON OF MAGNETIC BEHAVIOR OF Sr-HEXAFERRITE SYNTHESIZED BY CO-PRECIPITATION, SOL–GEL AND MICROWAVE COMBUSTION TECHNIQUES

Abstract

Single phase Sr -hexaferrite nanoparticles have been synthesized by three different techniques, co-precipitation, sol–gel combustion and microwave combustion. The structure of the powders indicates that heat treatment at 900°C is sufficient to form SrO · 6Fe2O3 single phase in all the three cases. The nanoparticles with typical dimensions of 10 nm × 50 nm × 200 nm are plate shaped and do not show any preferential alignment. The nanoparticles in all the cases exhibit a hard magnetic behavior at room temperature. The coercivity of microwave combustion synthesized Sr -hexaferrite particles is the largest, 5112 Oe while that of co-precipitation synthesized particles is 2668 Oe. The microwave combustion synthesized particles exhibit highest magnetization of 70.5 emu g-1 at room temperature in a field of 2.0 T.