Ukrainian Journal of Physical Optics

Number 4, Volume 2, 2001

Peculiarities of internal vibrational modes of Cs₂CdBr₄ crystal
Shchur Ya.I., Trach I.B., Vlokh O.G.

Institute of Physical Optics, Dragomanova 23, Lviv, 79005, Ukraine

Lattice dynamics study of Cs₂CdBr₄ crystal comprising both the Raman-scattering experiment and numerical simulation has been performed in the high-temperature orthorhombic phase (Pnma). The observation of extra Raman lines, forbidden by factor-group analysis reveals an existence of orientational disorder of the CdBr₄^2- groups. An interpretation of Raman spectra was made in the framework of a semi-empirical model taking into consideration the long-range Coulumbic, short-range and covalent interactions. The agreement between the theoretical and experimental phonon frequencies is reasonable.

Keywords: lattice dynamics, phonon, Raman spectra

doi 10.3116/16091833/2/4/192/2001

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