Recording potential of a single-domain particle

The ratio of the coercive force Hc to the effective energy barrier Uef is introduced to characterize the recording capability of a single-domain particle. It is shown that this ratio depends on the shape of the energy barrier separating equivalent energy minima. The optimal shape of the barrier is obtained for particles with uniaxial and combined (both uniaxial and cubic) types of magnetic anisotropy. For the optimal shapes, the gain in the ratio Hc/Uef can achieve 20%–40% with respect to the case of a Stoner–Wohlfarth particle.