Effect of interaction and anisotropy constant distribution on the magnetization processes of particulate media

Hysteresis loops of ensembles of dipole-dipole interacting single-domain particles were calculated. The hysteresis loop is smoothing with increasing particles volume fraction c. Coercive force Hcand remanence jRare decreasing linearly with increasing particles volume fraction (for small c). Anisotropy constant distribution don't effect on JRbut decrease Hc. In the case of log-normal distribution of anisotropy constants: Hc= = H° -aΔ, were Δ is the distribution width, a-constant.