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

Journal Article · Fri May 15 00:00:00 EDT 2015 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2015.01.047· OSTI ID:22475764

Niewiadomski, Adrian ^[1]; Kania, Antoni ^[1]; Kugel, Godefroy E. ^[2]; Hafid, Mustapha ^[3]; Sitko, Dorota ^[4]

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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)

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/ferrielectric phase transition.

• OSTI ID: 22475764
• Journal Information: Materials Research Bulletin, Vol. 65; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

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