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Title: A field theory of piezoelectric media containing dislocations

A field theory is proposed to extend the standard piezoelectric framework for linear elastic solids by accounting for the presence and motion of dislocation fields and assessing their impact on the piezoelectric properties. The proposed theory describes the incompatible lattice distortion and residual piezoelectric polarization fields induced by dislocation ensembles, as well as the dynamic evolution of these fields through dislocation motion driven by coupled electro-mechanical loading. It is suggested that (i) dislocation mobility may be enhanced or inhibited by the electric field, depending on the polarity of the latter, (ii) plasticity mediated by dislocation motion allows capturing long-term time-dependent properties of piezoelectric polarization. Due to the continuity of the proposed electro-mechanical framework, the stress/strain and polarization fields are smooth even in the dislocation core regions. The theory is applied to gallium nitride layers for validation. The piezoelectric polarization fields associated with bulk screw/edge dislocations are retrieved and surface potential modulations are predicted. The results are extended to dislocation loops.
Authors:
; ; ;  [1] ;  [2]
  1. Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux, Université de Lorraine/CNRS, Ile du Saulcy, 57045 Metz Cedex (France)
  2. Laboratory of Real Crystals, Institute of Solid State Physics, Russian Academy of Sciences, Chernogolovka, Moscow District, 2 Academician Ossipyan str., Chernogolovka 142432 (Russian Federation)
Publication Date:
OSTI Identifier:
22273627
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 14; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; EDGE DISLOCATIONS; ELECTRIC FIELDS; FIELD THEORIES; GALLIUM NITRIDES; LAYERS; MOBILITY; MODULATION; PIEZOELECTRICITY; PLASTICITY; POLARIZATION; SOLIDS; STRAINS; STRESSES; SURFACE POTENTIAL; TIME DEPENDENCE