Pressure effect on magnetic excitation in the Kondo semimetal CeNiSn

Effects of pressure and impurities on the magnetic excitation peak at ℎω = 4 meV are studied by neutron scattering on CeNiSn. The high pressure remarkably affects the magnetic excitation: at P = 6 kbar the excitation shifts to a higher energy region: at P = 11 kbar the excitation peak disappears below 7 meV. The increase of the peak energy at 6 kbar is consistent with the explanation by the particle-hole excitation over the hybridization gap. The sample quality, metallic or semiconducting, has no effect on the magnetic excitation spectrum. (orig.)