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Structure and properties of La-modified Na0.5Bi0.5TiO3 at ambient and elevated temperatures

Aksel, Elena and Forrester, Jennifer S. and Foronda, Humberto M. and Dittmer, Robert and Damjanovic, Dragan and Jones, Jacob L. (2012):
Structure and properties of La-modified Na0.5Bi0.5TiO3 at ambient and elevated temperatures.
In: Journal of Applied Physics, pp. 054111(1-8), 112, (5), ISSN 00218979, [Online-Edition: http://dx.doi.org/10.1063/1.4751357],
[Article]

Abstract

The crystal structure and property changes of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) piezoelectric ceramics are reported as a function of La modification (0.5–2.0 at. %) and increasing temperature using high resolution x-ray diffraction, permittivity, depolarization, and polarization and strain hysteresis measurements. La substitution is found to decrease the depolarization temperature of NBT (e.g., 1.5 at. % La substitution lowers the depolarization temperature by 60 °C relative to the unmodified composition) with little impact on the room temperature polarization and strain hysteresis. The room temperature structures of the various NBT compositions were modeled using a mixture of the monoclinic Cc space group and the cubic Pmmathm phase, where the Pmmathm phase is used to model local regions in the material which do not obey the long range Cc space group. With increasing La substitution, the lattice parameter distortions associated with the Cc phase approached that of the prototypical cubic unit cell and the fraction of the Pmmathm phase increased. The relationship between these crystallographic changes and the depolarization behavior of La-modified NBT is discussed.

Item Type: Article
Erschienen: 2012
Creators: Aksel, Elena and Forrester, Jennifer S. and Foronda, Humberto M. and Dittmer, Robert and Damjanovic, Dragan and Jones, Jacob L.
Title: Structure and properties of La-modified Na0.5Bi0.5TiO3 at ambient and elevated temperatures
Language: English
Abstract:

The crystal structure and property changes of sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) piezoelectric ceramics are reported as a function of La modification (0.5–2.0 at. %) and increasing temperature using high resolution x-ray diffraction, permittivity, depolarization, and polarization and strain hysteresis measurements. La substitution is found to decrease the depolarization temperature of NBT (e.g., 1.5 at. % La substitution lowers the depolarization temperature by 60 °C relative to the unmodified composition) with little impact on the room temperature polarization and strain hysteresis. The room temperature structures of the various NBT compositions were modeled using a mixture of the monoclinic Cc space group and the cubic Pmmathm phase, where the Pmmathm phase is used to model local regions in the material which do not obey the long range Cc space group. With increasing La substitution, the lattice parameter distortions associated with the Cc phase approached that of the prototypical cubic unit cell and the fraction of the Pmmathm phase increased. The relationship between these crystallographic changes and the depolarization behavior of La-modified NBT is discussed.

Journal or Publication Title: Journal of Applied Physics
Volume: 112
Number: 5
Divisions: 11 Department of Materials and Earth Sciences > Material Science > Nonmetallic-Inorganic Materials
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > A - Synthesis > Subproject A1: Manufacturing of ceramic, textured actuators with high strain
11 Department of Materials and Earth Sciences > Material Science
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue > A - Synthesis
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres > CRC 595: Electrical fatigue
11 Department of Materials and Earth Sciences
Zentrale Einrichtungen
DFG-Collaborative Research Centres (incl. Transregio) > Collaborative Research Centres
DFG-Collaborative Research Centres (incl. Transregio)
Date Deposited: 25 Sep 2012 12:28
Official URL: http://dx.doi.org/10.1063/1.4751357
Additional Information:

SFB 595 A1

Identification Number: doi:10.1063/1.4751357
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