Research on La3+-Co2+-substituted strontium ferrite magnets for high intrinsic coercive force

M-type strontium ferrites with substitution of Sr2+ by rare-earth La3+, and a little amount of Fe3+ by Co2+ according to the formula Sr1-xLaxFe12-xCoxO19, are prepared by the ceramic process. Effects of the substituted amount of La3+ and Co2+ on structure and magnetic properties of Sr1-xLaxFe12-xCoxO19 compounds have systematically been investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and B-H hysteresis curve measurements. In our results, the suitable amount of La3+-Co2+ substitution may remarkably increase saturation magnetization. Intrinsic coercive force (H-cj) of Sr ferrite magnets is evidently increased without significant decrease in residual flux density (B-r) by La3+-Co2+ substitution. (C) 2006 Elsevier B.V. All rights reserved.