The Vibration Spectrum of Rutile

Abstract

Raman effect data for rutile are evaluated for the force constants. It is shown that quasi-molecules TiO2 are formed with strong Ti–O bonds although every Ti atom is surrounded by 6 O atoms in about equal distances. The main force constants are (in 105 dynes/cm) 1.7 for the Ti–O bond of the quasi-molecules, 0.06 for the other Ti–O bonds, 0.2 for O–O bonds. The spectrum can be interpreted as that of coupled modified TiO2 molecules whose effective bond strength is a combination of the actual bond strengths.