Rotational hysteresis and magnetization curling of elongated single-domain particles in Alnico permanent magnets

The rotational hysteresis energy has been measured as a function of the applied field for Alnico IX with a preferred orientation and a single crystal of Ticonal 900. The results have been compared with the theoretical values obtained from the Stoner-Wohlfarth and Shtrikman-Treves theories, The results are in good general agreement with the Shtrikman-Treves theory, and from measurements of the rotational hysteresis integrals and the angular dependence of the coercivities it has been concluded that changes in the magnetization occur principally by the curling mechanism.