Synthesizing CoFe2O4 by Glass-Ceramic Method and Characterizing its Magnetic Properties in Na2O-Fe2O3-CoO-B2O3-SiO2 System

In this investigation، the effect of heat treatment on magnetic properties of glass and nano-structured cobalt-ferrite glass-ceramic was studied. The glass was synthesized in the system of Na2O-Fe2O3-CoO-B2O3-SiO2. Based on DTA results، heat treatment was done at different times and temperatures. X-ray diffraction pattern of glass-ceramic showed the crystallization of CoFe2O4 and some nonmagnetic phases. The highest magnetization of 11. 8 emu/g was obtained for the sample heat-treated for 2 hr at 670C in graphite bed. Average crystallite size of CoFe2O4 in this sample was 50 nm. Scanning Electron Microscopy (SEM) confirmed the formation of cobalt ferrite nanoparticles in the glass matrix.