QUASI-ONE-DIMENSIONAL ANTIFERROMAGNETIC CORRELATION IN THE KONDO SEMICONDUCTOR CENISN

Spin excitation of the Kondo semiconductor CeNiSn has been studied by neutron scattering in a wide Q space. Below the coherence temperature of 20 K, the excitation spectra show pronounced peaks at HBARomega = 4 and 2 meV, at Q = (Q(a), 1/2, Q(c)) and (0 0 1), respectively. The ob served Q dependence of the 4 meV excitation implies that the correspon ding dynamical antiferromagnetic-correlation is quasi-one-dimensional along the b-axis, and is polarized mainly along the a-axis.