Raman and infrared spectroscopy of Sr2BUO6 (B = Ni; Co) double perovskites

A.F.L. MOREIRA; A.F. GARCIA-FLORES; E. GRANADO; N.E. MASSA; R.M. PINACCA; J.C. PEDREGOSA; R.E. CARBONIO; A. MUNOZ; M.J. MARTINEZ-LOPE; J.A. ALONSO; L. DEL CAMPO; D. DE SOUSA MENESES; P. ECHEGUT

ELSEVIER SCIENCE BV

Año: 2010 vol. 54 p. 142 - 142

p class="MsoNormal" style="text-align: justify; line-height: 200%; margin: 0cm 0cm 0pt;">Temperature dependent normal modes and lattice thermal expansion of Sr2BUO6 (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