The various phases of the system Sr1-xCaxTiO3 - A Raman scattering study
| Autor: | Rajeev Ranjan, Sanjay Kumar Mishra, Ph. Pruzan, Dhananjai Pandey, J.-P. Pinan-Lucarre, R. Ouillon, P. Ranson |
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| Přispěvatelé: | Institut de minéralogie et de physique des milieux condensés (IMPMC), Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris Diderot - Paris 7 (UPD7)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), School of Materials Science and Technology, Institute of Technology, Banares Hindu University, Banaras Hindu University [Varanasi] (BHU), Université Pierre et Marie Curie - Paris 6 (UPMC)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2005 |
| Předmět: |
Condensed matter physics
Chemistry perovskites 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Ferroelectricity phase transitions symbols.namesake Tetragonal crystal system mixed compounds Nuclear magnetic resonance Phase (matter) 0103 physical sciences symbols Antiferroelectricity General Materials Science Orthorhombic crystal system ferro- and antiferroelectricity 010306 general physics 0210 nano-technology Raman spectroscopy Spectroscopy Raman scattering Phase diagram |
| Zdroj: | Journal of Raman Spectroscopy Journal of Raman Spectroscopy, 2005, 36, pp.898-911. ⟨10.1002/jrs.1383⟩ Journal of Raman Spectroscopy, Wiley, 2005, 36, pp.898-911. ⟨10.1002/jrs.1383⟩ |
| ISSN: | 0377-0486 1097-4555 |
| DOI: | 10.1002/jrs.1383⟩ |
| Popis: | This paper deals with the structural Raman-active and the disorder-induced TO and LO Raman modes in Sr1−xCaxTiO3 (SCT) ceramics. Spectra were recorded at ambient pressure in a wide range of temperatures from 8 K up to ≈500 K. The chemical composition (x) was chosen so as to investigate the phase boundaries which have been previously determined in the x-T phase diagram. An eigenvector analysis is given for all the known phases. The Raman data confirm the occurrence of a double-tilt system of Imma space group lying between the tetragonal I4/mcm and the orthorhombic Pbnm structures for x ≥ 0.06. Higher-order transformation of the antiferroelectric phase (0.20 ≤ x ≤ 0.40) at low temperature is also suggested. The main interesting disorder-induced effects originate from the temperature behaviour of the hard polar modes TO2 and TO4, which appear in the Raman spectra of the paraelectric domain. This behaviour allows one to discuss the precursor range of ferroelectricity in the SCT system in terms of ferroelectric- or antiferroelectric-type dipolar interactions. Copyright © 2005 John Wiley & Sons, Ltd. |
| Databáze: | OpenAIRE |
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