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Title: Raman spectroscopy, dielectric properties and phase transitions of Ag{sub 0.96}Li{sub 0.04}NbO{sub 3} ceramics

Highlights: • First Raman scattering studies of Ag{sub 0.96}Li{sub 0.04}NbO{sub 3}, allowed us to correlate temperature evolution of relaxational frequency γ{sub R}(T) with the Nb-ion dynamics and showed its changes at freezing temperature and ferrielectric transition. - Abstract: Silver lithium niobates Ag{sub 1−x}Li{sub x}NbO{sub 3} are promising lead free piezoelectrics. Good quality Ag{sub 0.96}Li{sub 0.04}NbO{sub 3} ceramics were obtained. Dielectric and DSC studies showed that, in comparison to AgNbO{sub 3,} temperatures of phase transitions slightly decrease. Dielectric studies pointed to enhancement of polar properties. Remnant polarisations achieves value of 0.6 μC/cm{sup 2}. Maximum of ϵ(T) dependences related to the relaxor-like ferroelectric/ferrielectric M{sub 1}–M{sub 2} transition becomes higher and more frequency dependent. Analysis of Raman spectra showed that two modes at 50 and 194 cm{sup −1} exhibit significant softening. Low frequency part of the Raman spectra which involve central peak and soft mode were analysed using two models. CP was assumed as relaxational vibration and described by Debye function. The slope of temperature dependences of relaxational frequency γ{sub R}(T) changes at approximately 470 and 330 K, indicating that slowing down process of relaxational vibrations changes in the vicinity of partial freezing of Nb-ion dynamics T{sub f} and further freezing at ferroelectric/ferrielectricmore » phase transition.« less
Authors:
 [1] ;  [1] ;  [2] ;  [3] ;  [4]
  1. A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice (Poland)
  2. LMPOS, University of Metz and Supelec Metz, 2 rue E. Belin, Metz 57070 (France)
  3. LPGC Dept. of Physics BP 133, Faculty of Science, Ibn Tofail University, 14000 Kenitra (Morocco)
  4. Institute of Physics, Pedagogical University, ul. Podchorazych 2, PL 30-084 Krakow (Poland)
Publication Date:
OSTI Identifier:
22475764
Resource Type:
Journal Article
Resource Relation:
Journal Name: Materials Research Bulletin; Journal Volume: 65; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; CALORIMETRY; CERAMICS; COMPARATIVE EVALUATIONS; DIELECTRIC PROPERTIES; FERROELECTRIC MATERIALS; FREQUENCY DEPENDENCE; LITHIUM COMPOUNDS; NIOBATES; PIEZOELECTRICITY; POLARIZATION; RAMAN EFFECT; RAMAN SPECTRA; RAMAN SPECTROSCOPY; SILVER COMPOUNDS; SLOWING-DOWN; TEMPERATURE DEPENDENCE