info:eu-repo/semantics/article
Raman and infrared spectroscopy of Sr2B′UO6 (B′ = Ni; Co) double perovskites
Fecha
2010-11Registro en:
Moreira, A. F. L.; García Flores, A. F.; Granados, E.; Massa, Nestor Emilio; Pinacca, Ruben Miguel; et al.; Raman and infrared spectroscopy of Sr2B′UO6 (B′ = Ni; Co) double perovskites; Elsevier Science; Vibrational Spectroscopy; 54; 2; 11-2010; 142-147
0924-2031
CONICET Digital
CONICET
Autor
Moreira, A. F. L.
García Flores, A. F.
Granados, E.
Massa, Nestor Emilio
Pinacca, Ruben Miguel
Pedregosa, Jose Carmelo
Carbonio, Raul Ernesto
Muñoz, A.
Martínez Lope, M. J.
Alonso, J. A.
del Campo, L.
De Sousa Meneses, D.
Echegut, P.
Resumen
Temperature dependent normal modes and lattice thermal expansion of Sr 2B′UO6 (B′ = Ni, Co) double perovskites were investigated by Raman/infrared spectroscopies and synchrotron X-ray diffraction, respectively. Monoclinic crystal structures with space group P21/n were confirmed for both compounds, with no clear structural phase transition between 10 and 400 K. As predicted for this structure, the first-order Raman and infrared spectra show a plethora of active modes. In addition, the Raman spectra reveal an enhancement of the integrated area of an oxygen stretching mode, which is also observed in higher-order Raman modes, and an anomalous softening of ∼1 cm-1 upon cooling below T* ∼ 300 K. In contrast, the infrared spectra show conventional temperature dependence. The band profile phonon anomalies are possibly related to an unspecified electronic property of Sr2B′UO6 (B′ = Ni, Co).