On the change of electronic states at the Fermi level by Ce doping in the intermetallic LaRu2

Variation of electronic structure at the Fermi level in superconducting LaRu2 intermetallic system has been studied by ri-lay absorption near edge structure (XANES) spectroscopy, The high resolution Ru K-edge XANES have been measured by fluorescence yield method using multi-element solid state detector assembly allowing to reach a signal to noise ratio of the order of Delta alpha/alpha similar to 10(-4). The results show that a doping by mixed valence Ce in place of La in the LaBu2 directly modifies the electronic states at the Fermi level leading to a decrease of the superconducting transition temperature, (C) 2001 Elsevier Science B.V. All rights reserved