Thermal hysteresis loops in spin-crossover compounds analyzed in terms of classical Preisach model

We apply the classical Preisach model to reproduce the major and minor thermal hysteresis loops in the high-spin /spl rlarr2/ low-spin transition for [Fe(bt)/sub 2/(NCS)/sub 2/]H/sub 2/O and Fe(bt)/sub 2/(NCS)/sub 2/ (bt=2,2'-bi-thiazoline). For this purpose, we consider that spin transition occurs through spin domains which are characterized by the up and down switching temperatures T/sub /spl alpha// and T/sub /spl beta// of a square-shaped thermal hysteresis loop. For each compound, we determine a Gaussian Preisach distribution P(T/sub /spl alpha//,T/sub /spl beta//) which fits the experimental data.