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Strontium based complex perovskites are potential candidates for microwave integrated circuit applications. In the present article, we report on Raman scattering studies of cubic and noncubic structures of Sr(B0.5′Nb0.5)O3 [B′=Ga, In, Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, and Yb] based complex-perovskite materials for an improved understanding of structure-property relations. The spectral results are compared to some tantalum analogues of known crystal structure. The present study reveals a higher degree of ordering for the tantalum compounds compared to those of the niobium analogues. Vibrational studies show a correlation between the tolerance factor and symmetry of these materials.

To obtain a sound basis for calculations of the lattice dynamics of chalcopyrite type compounds the literature data for the vibrational frequencies of 14 chalcogenides and 8 pnictides crystallizing in this structure are critically analysed. This is done by introducing frequency ratios of those frequencies which can be derived from zone centre or zone boundary vibrations of the sphalerite lattice presuming similar bonding and normal co-ordinates in all compounds investigated. Based on the reliable spectra vibrational frequencies have been calculated for those compounds which have not yet been investigated or for which the results given in the literature are uncertain.

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