کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5160852 | 1501686 | 2017 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Temperature and composition induced phase transitions in Sr2âxCa1+xTeO6 (0 â¤Â x â¤Â 2) double perovskite oxides
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آلی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Structures of Sr2âxCa1+xTeO6 double perovskites have been studied by the profile analysis of X-ray diffraction data and Raman spectroscopy at room temperature. This series adopts a monoclinic symmetry for the compositions (0 â¤Â x â¤Â 0.5) with P21/n as space group and a triclinic system with P1¯ space group for the compositions (0.5 < x â¤Â 2). These results were confirmed by the observed tolerance factor calculated from the distances obtained from the Rietveld refinements which indicates that the true tilt system for the compositions range (0.5 < x â¤Â 2) is the triclinic tilt system. Clear changes in the Raman modes centered at 600, 610 and 620 cmâ1 and the FWHM of OTeO bending vibrations, centered at 738 cmâ1 confirmed that the triclinic symmetry takes place between the compositions x = 0.5 and x = 1. Furthermore, Raman spectroscopy studies at high temperature were done for Ca3TeO6. For this compound, considerable changes in the temperature dependence of the modes were well illustrated.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Molecular Structure - Volume 1131, 5 March 2017, Pages 103-113
Journal: Journal of Molecular Structure - Volume 1131, 5 March 2017, Pages 103-113
نویسندگان
Y. Tamraoui, Bouchaib Manoun, F. Mirinioui, I. Saadoune, R. Haloui, A. Elhachmi, E. Saad, P. Lazor,