RAMAN-STUDY OF TETRAGONAL TUNGSTEN DISILICIDE

After a brief report of recent WSi2 Raman results on the band assignme nt and thermal behavior of the WSi2 lines obtained for both a single c rystal and a thin film, a calculation of vibrational frequencies and n ormal coordinates at the zone center is presented. The first results s how good agreement between observed and calculated frequencies, and co nfirm our previous description of vibrational modes, The corresponding force constants relative to Si-Si and W-Si bonds are found to be diff erent while the bond lengths are very close. The present results will be used in future calculations at the zone boundary.