Magnetisation reversal in Sm2Fe17N3 particles

The initial magnetization curves of Sm2Fe17N3 particles having different average particle size have been measured at 15 K, in applied fields up to 10 T. Several magnetization processes may be observed: domain-wall motion in low fields, magnetization reversal of single-domain particles observed in intermediate fields and only in the samples with the smallest particle size, and progressive rotation of magnetic moments in high fields. The variation of the low-field susceptibility in the different samples is discussed and numerical simulation of magnetization reversal is obtained. (orig.)