Abstract:
Raman spectroscopy was employed to investigate the structures and phonon modes of Ba2InTaO6 and Sr2InTaO6 ceramics. It was found that Ba-based samples belong to the tetragonal P4/mnc (#128 or D-4h(6)) space group, while Sr-based materials belong to the monoclinic P2(I)/n (#14 or C-2h(5)) space group. Low-temperature measurements did not show any phase transition down to 77K. Lorentzian lines were used to fit the experimental data, which presented 14 phonon modes for Ba2InTaO6 and 24 modes for Sr2InTaO6, in perfcct agreement with the theoretical factor-group analyses for the proposed structures. This paper reports, for the first time, a tetragonal P4/mnc structure for an indium-containing perovskite material.
