Analysis of Transition-Metal-Silicon Distances and Types of Chemical Bonding in Binary Transition-Metal Silicides

摘要

X-ray spectroscopy data on the electronic structure of binary silicides of the 3d and 4d transition metals and calculated energy-band structures of these compounds are consistent with the variation of interatomic distances and indicate that an increase in the silicon content is accompanied by an increase in the density of states in the low-energy part of the valence band, whereas an increase in the transition-metal content leads to an increase in the density of states in the high-energy part. The features of the density of states determine the character of M-Si chemical bonding and its variation from purely metallic to metallic with a considerable covalent contribution in the series M_3Si, M_5Si_3, MSi, and MSi_2.