Synthesis of Co-B/resin nanoparticles and heat treatment effect on their magnetic properties

The particle size and magnetic properties of Co-B nanoparticles in polymeri c resin with B concentrations of 3.04 and 4.38 wt% before and after heat tr eatment were investigated by various techniques. X-ray diffraction results reveal that the Co-B nanoparticles are a mixture of part crystalline and pa rt amorphous phase. Transmission electron microscopy shows that the particl e size of Co-B nanoparticles encapsulated in resin is increased by the incr ease of Co2+ ions exchange and reduction times. Decomposition temperature o f the resin is about 460 degrees C, so the heat treatment effect at 250 and 390 degrees C on their magnetic properties is also studied. X-ray diffract ion and vibrating sample magnetometer results demonstrated that the crystal linity, magnetization and coercivity can be affected by heat treatment temp erature. (C) 2000 Elsevier Science B.V. All rights reserved.