VIBRATIONAL STUDY OF TIH2ASO4, TIH2PO4 AND THEIR DEUTERATED ANALOGS

The Raman and infrared spectra of polycrystalline samples TIH//2AsO//4, TID//2AsO//4, TIH//2PO//4 and TID//2PO//4 have been investigated at 300 K in the frequency ranges 0 to 4000 and 200 to 4000 cm** minus **1 respectively. The assignment of lattice, internal, and OH group vibrations has been approximated in terms of symmetry species. Although all the vibrations follow more or less the space group symmetry, the internal vibrations do not completely fulfill the requirements of the symmetry rule. The isotope effect was observed prominently on both compounds in Raman and infrared spectra. An attempt has been made to assign and explain the results.