CO-SN SUBSTITUTED BARIUM FERRITE PARTICLES

Co-Sn substituted barium ferrite particles, BaFe12-2xCoSnxO19 (0 less- than-or-equal-to x less-than-or-equal-to 1.4), have been investigated using x-ray, VSM, and Mossbauer spectroscopy. The magnetocrystalline-a nisotropy constant has been determined as a function of x from an anal ysis of the approach to magnetic saturation. Mossbauer spectra indicat e that Co2+ and Sn4+ ions have a strong preference for the 2b, 4f(VI), and 12k sites. The reduced anisotropy constants k = K1(x)/K1(0) have been calculated based on the single-ion model and the site preferences and agree well with the measured values. The origin of the magnetic c hanges caused by Co2+ and Sn4+ substitution can be attributed to the s ite preferences.