NMR Study of Magnetic Excitations in CeNiSn

Abstract

The anisotropies of the Knight shift and the nuclear spin-lattice relaxation time (T₁) at the Sn sites have been measured up to 300, K with a magnetically aligned powder sample of CeNiSn. In contrast to the results of previous neutron scattering measurements, the anisotropy of 1/T₁ is weak and almost temperature (T)-independent. This indicates that the substantial spectral weight exists in the higher energy region than the quasielastic magnetic excitation at high T. Above about 60, K, 1/T₁ increases linearly with T, suggesting that the T dependence of the quasielastic line width is weak.