Raman and infrared spectroscopy of Sr2B′UO6 (B′ = Ni; Co) double perovskites

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, w...

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Detalles Bibliográficos
Autores: 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.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2010
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/67485
Acceso en línea:http://hdl.handle.net/11336/67485
Access Level:acceso abierto
Palabra clave:DOUBLE PEROVSKITES
INFRARED REFLECTIVITY
RAMAN SCATTERING
SYNCHROTRON X-RAY POWDER DIFFRACTION
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Descripción
Sumario: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).