The isothermal remanent magnetisation of particulate media

A model is presented of the remanent magnetisation of a system of non-interacting Stoner-Wohlfarth particles with differing degrees of orientational texture. IRM curves are calculated which are used ho show the effect of a finite magnetising field on the determination of optimum values of diameter and anisotropy constant. The shape of the SFD is also found to depend strongly on the degree of orientational texture. The width of the SFD is increased or decreased relative to the aligned case depending on whether the intrinsic SFD for the aligned system is small or large respectively.