The magnetic anisotropy of an aligned MnAlC magnet

Abstract

The magnetic anisotropy constants K1 and K2 have been measured for an aligned MnAlC magnet. The information is extracted from magnetization curves with the magnetic field parallel and perpendicular to the alignment axis. The anisotropy field HA =2(K1+2K2)/IS (IS is the saturation magnetization) was determined from a break point in a plot of the perpendicular magnetization against the inverse square of the field. K1 and K2 were then found from modified Sucksmith–Thomson plots. The data is used to calculate the 180° wall energies and widths and an estimate of the temperature coefficient of coercive field variation is made and compared with experiment.