Structural and Magnetic Properties of New Type Ca<i>_x</i>Sr_1-<i>_x-y</i>La<i>_y</i>O•<i>n</i>Fe_(2n-z)/<i>_n</i>Co<i>_z/n</i>O₃ Magnets

Abstract

Considering that Ca 2+ has the similar ion radius and the substituted ability as Sr 2+ and Ba 2+ but the same family, Ca x Sr 1- x-y La y O• n Fe (2n-z)/ n Co z/n O 3 ferrites have been synthesized by the conventional ceramic process. Structure and magnetic properties of Ca x Sr 1- x-y La y O• n Fe (2n-z)/ n Co z/n O 3 compounds have systematically been investigated by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), scanning electron microscope (SEM) and B - H hysteresis curve measurements. Several compositions are selected to investigate the formation of M phase with the joint replacement of Ca-La-Co. It is found that the formation mechanism is based on the replacement of Sr 2+ by La 3 + plus Ca 2+ and the charge compensation by Co 2 + . In futher results, the unexpectedly intrinsic coercivity of 436 kA/m and residual flux density of 0.445 T were obtained. In terms of material preparation, we believe that Ca x Sr 1- x-y La y O• n Fe (2n-z)/ n Co z/n O 3 is effective in the production of future high energy permanent magnets.