Second-Order Raman Spectra of Thorium Dioxide

Abstract

The second-order Raman spectra of the thorium dioxide crystal have been investigated. The results are interpreted in terms of the phonon energies near the Brillouin zone boundaries and the zone center, which have been calculated by using Born-von Karman force model. A nearly complete interpretation of the spectra is given. The observed polarization of Raman spectra is in good agreement with the calculated selection rules for the second-order Raman process at the symmetric points Γ, M and L.