Raman spectra of CuGa3Te5 ordered‐defect compound

Raman spectra of CuGa3Te5 that has a chalcopyrite-related structure with space group P4¯2c were obtained at room temperature from measurements performed under parallel (z|xx|z) and perpendicular (z|xy|z) polarization dependent configurations. A tentative assignment of the observed lines was made by comparison with the reported phonon modes for ZnTe, which is the binary analogue of CuGaTe2, and also by using theoretical models reported in the literature for multinary compounds. The main lines observed at 129, 144, and 187 cm−1 were assigned to the three A1-symmetry modes for P4¯2c ternary compounds predicted by group theory, and other lines at 91 and 277–285 cm−1 to the B1 modes. Also, lines at 55, 64, 102, 172, 224, 265–269, and 333–334 cm−1 and lines at 78, 172, 224, 205–209, 242–249, and 342 cm−1 were assigned to E and B2 modes, respectively. The higher-phonon frequencies observed at 291–297, 303–310, and 319–323 cm−1 are attributed to an overtone of the A1 mode at 144 cm−1, and a combination of A1 and E modes, respectively.