K beta-to-K alpha X-ray intensity ratio studies on the changes of valence electronic structures of Ti, V, Cr, and Co in their disilicide compounds

K beta-to-K alpha X-ray intensity ratios of Ti, V, Cr, and Co in pure metal s and their disilicide compounds have been measured following excitation by 59.54 keV gamma-rays from a 200 mCi Am-241 point-source. The K beta-to-K a lpha intensity ratios of all these metals in the disilicide compounds are f ound to be less than the corresponding ratios for pure metals. Comparison o f the measured K beta-to-K alpha intensity ratios for the disilicides and p ure metals with the multiconfiguration Dirac-Fock calculations indicates in crease of the 3d electron populations of Ti, V, Cr, and Co in the disilicid es from their pure metal values suggesting the rearrangement of electrons b etween 3d and 4s states of the individual metal atom. This rearrangement is found to be opposite to that observed in our previously reported work on N iSi2 and CuSi2. (C) 1999 Elsevier Science B.V. All rights reserved.