Thermomagnetics of interacting magnetic particles

Thermomagnetics of a system of interacting particles with log normal distribution of particle size and anisotropy constant was studied self-consistently using a Monte Carlo calculation within the mean-field approximation. Characteristic hysteretic behavior and reversible transverse susceptibility (RTS) were investigated. The salient features are as follows: The hysteresis loops become sheared with increasing anisotropy distribution, /spl sigma//sub K/, while their slopes steepen with the mean field strength /spl alpha/. For a homogeneous systems RTS peaks increase sharply with /spl alpha/, both at the anisotropy field H/sub K/ and coercive field H/sub c/. For random systems, both peaks become shallower and blunted with increasing /spl sigma//sub K/. Mean field strength /spl alpha/ causes the peak positions of RTS at H/sub K/ to shift to lower values, while the shift at H/sub c/ depends subtly upon the interplay among /spl alpha/, /spl sigma//sub K/ and texture of the system. For random systems the shift is toward higher H/sub c/ values with increasing /spl alpha/. For systems with constant /spl alpha/, however, it shifts toward lower values with increasing /spl sigma//sub K/.