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.

The enthalpy contents of leadchalcogenides at temperatures between 300°K to their melting points were measured. Enthalpies of mixing in the liquid state (for mole fractions of chalcogen = 0.5) were calculated. These values confirm the more metallic character of the melts with tellurium as one constituent element and the more covalent character of the sulfide containing melts.

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The halogenobismuthates Q3Bi2X9 (Q = EtMe2PhN; X = Cl, Br, I) were prepared by reaction of BiX3 with EtMe2PhNX in ethanol. Single crystal structure determinations yielded: [EtMe2PhN]3[Bi2Cl9], S.G. P212121, Nr. 19, a = 952.5(3), b = 1184.1(4), c = 3726.4(9 pm, Z = 2;[EtMe2PhN]3[Bi2Br9] S.G .P21/c , No. 14, a= 1839.4(4),b= 1329.5(3), c = 1817.3(6)pm, β = 92.68(3)°, Z = 4, [EtMe2PhN]3[Bi2l9], ], S.G . P21/c, No. 14, a = 1915.3(2), b = 1379.0(3), c = 1890.9(5) pm, β = 92.48(1)°, Z = 4. The thermal behaviour was investigated with the aid of DSC measurements and temperature dependent X-ray powder diffraction. All compounds undergo a transition into a high temperature modification which could be obtained in case of [EtMe2PhN]3[Bi2Br9-xIx] in form of single crystals: S.G . P21/c, Nr. 14, a = 1002.7(5), b = 1278.7 (8), c = 3584.3(5) pm, β = 90.12(2)°, Z = 4. Surprisingly in this compound the iodine atoms are not statistically distributed over all possible bromine positions, but occupy only one position. Lattice parameters of the other high temperature modifications and enthalpies of transition of the compounds are given. In addition a second iodobismuthate was isolated:[EtMe2PhN]4[Bi6l22], S.G . P1̄, Nr. 2 , with lattice parameters of a = 1343.4(3), b = 1554.3(3), c = 2262.5(6) pm, a = 100.89(3)°, β = 96.63(1)°, 7 = 98.94(2)° and Z = 2.