High‐Temperature Raman Spectra and Thermal Expansion of Wollastonite

Abstract

Unpolarized single‐crystal Raman spectra in the temperature interval of 298–1235 K and powder X‐ray diffractometry data from room temperature up to 1295 K have been obtained from a natural triclinic wollastonite of almost‐ideal composition. Room‐temperature spectra, along with the temperature dependencies of nine major Raman modes, are presented. The temperature shifts of the Raman modes indicate a discontinuity in the temperature range of 950–980 K. No corresponding changes are observed in the temperature dependencies of the lattice parameters. Thermal expansion coefficients for the lattice parameters in the temperature range of 298–1295 K are given.