THE EFFECT OF GRAIN SIZE ON SATURATION MAGNETIZATION OF BARIUM FERRITE POWDERS *

Abstract

Studies on barium ferrite powder showed a decrease in saturation magnetization with decreasing grain size. This phenomenon had previously been observed in iron and magnetite powders and was attributed to the existence of a disturbed layer on the individual powder grains (Hüttig's surface layer). This layer may vary in thickness according to the manufacturing process used, and the degree of disturbance will increase with the fineness of the powders.