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Title: Defect-dipole alignment and tetragonal strain in ferroelectrics

Abstract

We show the alignment of defect dipoles along the direction of the spontaneous polarization in polycrystalline Pb(Zr,Ti)O{sub 3} and BaTiO{sub 3} ferroelectric ceramics using electron paramagnetic resonance (EPR). The alignment is demonstrated via orientation dependent paramagnetic centers in the polycrystalline materials and computer modeling of the EPR line shapes. It is shown that defect dipoles can become aligned by oxygen vacancy motion in the octahedron about a negatively charged center for the oxygen vacancy-related dipole complexes or by defect displacement and domain realignment in the lattice for isolated defect centers. We find that the alignment is not observed in nonferroelectric materials such as SrTiO{sub 3}, and is destroyed in ferroelectric materials by heating above the Curie temperature. These observations suggest an interplay between distortion in the unit cell and the ability to align defect dipoles, as is the case more generally for ferroelectric dipole alignment. We also directly observe aligned intrinsic Ti and Pb ion displacements in the ferroelectric Pb(Zr,Ti)O{sub 3} perovskite unit cell. {copyright} {ital 1996 American Institute of Physics.}

Authors:
; ; ; ;  [1];  [2]
  1. Sandia National Laboratories, Albuquerque, New Mexico 87185-1349 (United States)
  2. Cambridge University, Engineering Department, Cambridge CB2-IPZ (United Kingdom)
Publication Date:
Research Org.:
Sandia National Laboratory
OSTI Identifier:
284646
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 79; Journal Issue: 12; Other Information: PBD: Jun 1996
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; FERROELECTRIC MATERIALS; STRAINS; PZT; BARIUM COMPOUNDS; TITANATES; ELECTRON SPIN RESONANCE; POLYCRYSTALS; CRYSTAL DEFECTS; POLARIZATION; HEATING; ELECTRIC DIPOLES; BARIUM TITANATES

Citation Formats

Warren, W L, Pike, G E, Vanheusden, K, Dimos, D, Tuttle, B A, and Robertson, J. Defect-dipole alignment and tetragonal strain in ferroelectrics. United States: N. p., 1996. Web. doi:10.1063/1.362600.
Warren, W L, Pike, G E, Vanheusden, K, Dimos, D, Tuttle, B A, & Robertson, J. Defect-dipole alignment and tetragonal strain in ferroelectrics. United States. doi:10.1063/1.362600.
Warren, W L, Pike, G E, Vanheusden, K, Dimos, D, Tuttle, B A, and Robertson, J. Sat . "Defect-dipole alignment and tetragonal strain in ferroelectrics". United States. doi:10.1063/1.362600.
@article{osti_284646,
title = {Defect-dipole alignment and tetragonal strain in ferroelectrics},
author = {Warren, W L and Pike, G E and Vanheusden, K and Dimos, D and Tuttle, B A and Robertson, J},
abstractNote = {We show the alignment of defect dipoles along the direction of the spontaneous polarization in polycrystalline Pb(Zr,Ti)O{sub 3} and BaTiO{sub 3} ferroelectric ceramics using electron paramagnetic resonance (EPR). The alignment is demonstrated via orientation dependent paramagnetic centers in the polycrystalline materials and computer modeling of the EPR line shapes. It is shown that defect dipoles can become aligned by oxygen vacancy motion in the octahedron about a negatively charged center for the oxygen vacancy-related dipole complexes or by defect displacement and domain realignment in the lattice for isolated defect centers. We find that the alignment is not observed in nonferroelectric materials such as SrTiO{sub 3}, and is destroyed in ferroelectric materials by heating above the Curie temperature. These observations suggest an interplay between distortion in the unit cell and the ability to align defect dipoles, as is the case more generally for ferroelectric dipole alignment. We also directly observe aligned intrinsic Ti and Pb ion displacements in the ferroelectric Pb(Zr,Ti)O{sub 3} perovskite unit cell. {copyright} {ital 1996 American Institute of Physics.}},
doi = {10.1063/1.362600},
journal = {Journal of Applied Physics},
number = 12,
volume = 79,
place = {United States},
year = {1996},
month = {6}
}