(1) Institut Laue Langevin, Grenoble, France;(2) Institut für Theoretische Physik, R.W.T.H. Aachen, D-5100 Aachen, Federal Republic of Germany;(3) Department of Physics, L.U.T. Loughborough, LE11 3TU, Leicestershire, UK
Abstract:
Two samples of CeCuxSi2 withx=1.8 (non superconducting) andx=2.2 (superconducting) have been investigated by neutron powder diffraction. Both samples were characterized crystallographically and then their impurity content and lattice site occupation were determined. Anisotropic thermal vibrations of the Cu and Si atoms is detected at low temperatures. A relationship between the structural parameterz (defining the distance Ce to Si) and the occurance of superconductivity is suggested.