%0 Journal Article
%K Raman
%K Spectra
%K Spectrum
%A Eric Faulques
%A Richard E Russo
%B Solid State Communications
%D 1992
%F Laser
%G eng
%N 7
%P 531-535
%R 10.1016/0038-1098(92)90226-Y
%T Raman spectra of iodide species in intercalated IBi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>8+δ</sub>
%V 82
%8 05/1992
%X <p>We report Raman spectra of pristine Bi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>8+δ</sub> single crystals. Low frequency spectra of the intercalated crystal taken at room and liquid nitrogen temperatures with the 488 nm Ar<sup>+</sup> excitation line exhibit a strong band at 105 cm<sup>-1</sup> and weaker bands at ≈ 73 and ≈ 150 cm<sup>-1</sup>. The results are confirmed by using the 647 nm Kr<sup>+</sup> excitation line. These bands characterize the fundamental vibrations of I<sub>3</sub>-molecular anions embedded in the lattice. Drastic change of the micro-Raman scattering in the 200–700 cm<sup>-1</sup> region is observed between pristine and iodinated crystals. A factor group analysis of stage-1 IBi<sub>2</sub>Sr<sub>2</sub>CaCu<sub>2</sub>O<sub>8+δ</sub> is presented based on possible structures and predicts that iodine vibrations can be Raman active in a non-centrosymmetric lattice.</p>