Charge transfer studies in V3Si, Cr3Si and FeSi

Abstract

Kβ-to-Kα X-ray intensity ratios of V, Cr and Fe in pure metals and in V3Si, Cr3Si and FeSi have been measured for understanding the charge transfer / delocalization phenomena in the silicide compounds. Comparison of the measured ratios for V with Multi Configuration Dirac–Fock calculations indicates a small amount of charge transfer (0.54±0.25 electrons per V atom) from vanadium to silicon in V3Si which is in qualitative agreement with the results of LCAO band structure calculation of Bisi and Chiao (O. Bisi and L.W. Chiao, Phys. Rev. B, 25 (1982) 4943). However, previous experimental studies on charge density, Compton profile and theoretical calculations based on linear APW method suggested charge transfer from Si to V with differing amounts which disagree with our present result. Alternatively the result for V3Si can also be explained as due to rearrangement of electrons between 3d and 4s states of vanadium. Our result for Cr3Si suggests an increase of 3d electrons of Cr by about 1.02±0.32 either due to transfer of electrons from Si to Cr or transfer of electrons from 4s state to 3d state of Cr. Our experimental result for FeSi suggests no change in the valence electronic structure of Fe.