Unusual temperature dependence of the magnetic anisotropy constant in barium ferrite BaFe12O19

摘要: We report magnetic hysteresis loops in a wide temperature range (4-700 K) for silica-coated barium ferrite BaFe12O19 nanoparticles. The saturation magnetization Ms and the first anisotropy constant K are determined simultaneously from loop using law of approach to saturation. It is remarkable that linearly proportional varies precisely with as K(T) = K(0)[1 − (T/TC)1.58] whole below Curie TC (740 K). unusual dependence its linear relation not predicted existing theoretical models.