The switching mechanism in BaFe particles

The magnetization switching mechanisms in barium-ferrite particles are examined using numerical micromagnetic calculations. When the particle's aspect ratio is large, the observed reversal starts at the center of the BaFe platelet and is referred to as central switching. For smaller aspect ratios the coherent rotation mode is observed. The coercivity for BaFe particles is given and is compared with the classical values. The classical Stoner-Wolfarth formula, which used the oblate ellipsoidal demagnetizing factors, is found to introduce considerable errors for the coercivity and is corrected.>