Magnetic Properties of CeBi, NdBi, TbBi, and DyBi

Abstract

The magnetic properties of four REBi compounds, where RE is Ce, Nd, Tb, and Dy, were investigated by neutron diffraction on powder samples; all of these compounds are antiferromagnetic below Néel temperatures T_N of 26, 25, 18, and 13°K, respectively. The magnetic structure of both CeBi and NdBi consists of (001) ferromagnetic planes coupled antiferromagnetically with the spin direction along the [001] axis. TbBi has a magnetic structure which consists of (111) ferromagnetic planes coupled antiferromagnetically with a [111] spin direction. The magnetic structure of DyBi could be either type A or B of MnO; the spin direction could not be determined from the present powder sample. CeBi and NiBi possess antiferromagnetic ordering of the first kind whereas TbBi and DyBi have the second kind. The development of antiferromagnetic ordering below T_N follows a Brillouin function for CeBi and NdBi but TbBi and DyBi show considerable deviation. The saturation ordered moments for CeBi and NdBi are 6% less than the calculated values whereas for TbBi and NdBi the moments are 12% less than the expected values.