Magnetization and specific heat studies of RNi4Ga (RSm, Gd and Tb)

Abstract In order to elucidate the anomalous magnetic properties in the ferromagnetically ordered state of SmNi 4 Ga GdNi 4 Ga and TbNi 4 Ga, we have carried out a detailed study with magnetization and specific heat (SH) measurements. GdNi 4 Ga shows the possibility of a filled 3d band and a helical spin arrangement below the ordering temperature. TbNi 4 Ga shows a dominant crystal field effect resulting in a deviation of T C from the de-Gennes scaling and possible Schottky anomalies in the SH. SmNi 4 Ga shows a large coercivity at low temperatures. A rough estimate of the domain wall thickness in SmNi 4 Ga gives a value of 8 A.