STRUCTURE AND IR AND RAMAN POLARIZED SPECTRA OF BALAGA3O7 SINGLE-CRYSTALS

X-ray diffraction analysis was applied to a BaLaGa3O7 single crystal o btained by the Czochralski technique. It crystallizes in the tetragona l system with the space group P (4) over bar 2(1)m (D-2d(3)) and two f ormula units in the unit cell of dimensions a = 8.145 (2), c = 5.382 ( 2) Angstrom at 300 K. Polarized IR transmission and Raman scattering s pectra of oriented single crystals were measured and are discussed in terms of factor group analysis and x-ray structure. A vibrational assi gnment is proposed.