CRYSTAL-STRUCTURE OF BA0.39SR0.61NB2O6 SINGLE-CRYSTALS

The atomic structure of the barium-strontium niobate BaxSr1-xNb2O6 (BS N) solid solution with x = 0.39 has been studied by single crystal X-r ay diffraction method (a = 12.456(1), c = 3.936(2) Angstrom, sp. gr. P 4bm, Z = 5, R = 2.17%, R-w = 2.20). The structure parameters obtained are compared with the characteristics of the BSN solid solution with x = 0.27 and 0.67, which was studied earlier, It is shown that the stru ctures obtained in all three known X-ray studies (x = 0.27, 0.39, and 0.67) have the same frameworks of NbO6-octahedra with Ba and Sr cation s located differently in two types of channels of these three-dimensio nal frameworks.