Microstructures, physical and magnetic properties of BaFe12O19 permanent magnets with the addition of Al2O3-MnO

Abstract

Barium hexaferrite (BaFe12O19) permanent magnets with the addition of Al2O3-MnO (0.12, 0.24; and 0.42 wt%) have been prepared by mechanical alloying method. The addition of Al2O3-MnO was done in order to improve the density and mechanical properties of the fabricated BaFe12O19 permanent magnet. Particle size of the as-mixed powder decreases Al2O3-MnO concentration increases. The as-mixed powders was then compacted into pellets and sintered at 1000 and 1100 °C for 2 hours. The crystalline phases and morphology of the pellets were observed using X-ray diffraction (XRD) and Scanning electron microscopy (SEM), respectively. It is found that the increase of the sample hardness has correlation with the bulk density of the samples. While, the flux density decreases linearly as Al2O3- MnO additives increases. The analysis of hysteresis curves classified the pellets as a hard magnet.