Na1−xLixNbO3 ceramics studied by X-ray diffraction, dielectric, pyroelectric, piezoelectric and Raman spectroscopy |
| |
Authors: | Chiheb Chaker Walid El Gharbi Annie Simon Mario Maglione |
| |
Affiliation: | a Laboratoire des Matériaux Ferroélectriques (LMF), Unité de Recherche Physique-Mathématiques 05UR15-04, Université de Sfax, Faculté des Sciences de Sfax (FSS), Route de Soukra km 3.5, BP 1171, 3000 Sfax, Tunisie b Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), CNRS, Université de Bordeaux, 87 Avenue du Dr. A. Schweitzer, Pessac F-33608, France |
| |
Abstract: | Na1−xLixNbO3 ceramics with composition 0.05≤x≤0.30 were prepared by solid-state reaction method and sintered in the temperature range 1100-1150 °C. These ceramics were characterised by X-ray diffraction as well as dielectric permittivity measurements and Raman spectroscopy. Dielectric properties of ceramics belonging to the whole composition domain were investigated in a broad range of temperatures from 300 to 750 K and frequencies from 0.1 to 200 kHz. The Rietveld refinement powder X-ray diffraction analysis showed that these ceramics have a single phase of perovskite structure with orthorhombic symmetry for x≤0.15 and two phases coexistence of rhombohedral and orthorhombic above x=0.20. The evolution of the permittivity as a function of temperature and frequency showed that these ceramics Na1−xLixNbO3 with composition 0.05≤x≤0.15 present the classical ferroelectric character and the phase transition temperature TC increases as x content increases. The polarisation state was checked by pyroelectric and piezoelectric measurements. For x=0.05, the piezoelectric coefficient d31 is of 2pC/N. The evolution of the Raman spectra was studied as a function of temperatures and compositions. The results of the Raman spectroscopy study confirm our dielectric measurements, and they indicate clearly the transition from the polar ferroelectric phase to the non-polar paraelectric one. |
| |
Keywords: | A. Ceramics C. X-ray diffraction C. Raman spectroscopy D. Ferroelectricity D. Phase transitions |
本文献已被 ScienceDirect 等数据库收录! |
|