We studied temperature dependence of complex capacitance, impedance, and polarized Raman spectra of single crystal Cs2Nb4O11. First, we observed a sharp-shaped peak at 165 oC in the complex capacitance, then found drastic changes in the Raman spectra in the same temperature range. Utilizing the pseudosymmetry search of structure space group, we attributed the observed anomalies to a structural change from the room temperature orthorhombic Pnn2 to another or- thorhombic Imm2. We also measured room temperature polarized Raman spectra in different symmetries of normal vibrations and assigned high wavenumber Raman bands to the internal vibrations of NbO6 octahedra and NbO4 tetrahedra.
Liu, Jianjun; Kharitonova, E. P.; Duan, Chun-Gang; Mei, Wai-Ning; Smith, Robert W.; and Hardy, John R., "Electrical properties and Raman Scattering Study of Single Crystal Cs2Nb4O11" (2004). Chemistry Faculty Publications. 7.