Study of zone center phonons in wolframite ZnWO_4

Authors: RUBY JINDAL, MURARI MOHAN SINHA, HEM CHANDRA GUPTA

Abstract: A short-range force constant model was applied to investigate the phonons in wolframite ZnWO_4 crystals in their monoclinic phase having space group P2/c and symmetry C_{2h}. The normal symmetry coordinates for the monoclinic wolframite were computed. The zone center phonons were calculated by using 8 stretching and 6 bending force constants. The calculated results are in very good agreement with the observed ones. The infrared frequencies were assigned for the first time. The potential energy distribution was also investigated for determining the significance of the contribution from each force constant toward the Raman and infrared wavenumbers.

Keywords: Lattice dynamics, infrared spectra, Raman spectra, zone center phonons, wolframite structure

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