Charged dislocations in piezoelectric bimaterials

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:51

Article

Han, Xueli¹  Pan, Ernie²  Sangghaleh, Ali²  Albrecht, John³ 

[1] Beijing Inst Technol, Sch Aerosp, Beijing 100081, Peoples R China

[2] Univ Akron, Comp Modeling & Simulat Grp, Akron, OH 44325 USA

[3] Michigan State Univ, Dept Elect & Comp Engn, E Lansing, MI 48824 USA

关键词: Charged dislocation;    Anisotropic bimaterial;    Piezoelectricity;    Polarization;   

DOI  :  10.1016/j.ijsolstr.2014.03.035

来源: Elsevier

【 摘 要 】

In some piezoelectric semiconductors and ceramic materials, dislocations can be electrically active and could be even highly charged. However, the impact of dislocation charges on the strain and electric fields in piezoelectric and layered structures has not been presently understood. Thus, in this paper, we develop, for the first time, a charged three-dimensional dislocation loop model in an anisotropic piezoelectric bimaterial space to study the physical and mechanical characteristics which are essential to the design of novel layered structures. We first develop the analytical model based on which a lineintegral solution can be derived for the coupled elastic and electric fields induced by an arbitrarily shaped and charged three-dimensional dislocation loop. As numerical examples, we apply our solutions to the typical piezoelectric AlGaN/GaN bimaterial to analyze the fields induced by charged square and elliptic dislocation loops. Our numerical results show that, except for the induced elastic (mechanical) displacement, charges along the dislocation loop could substantially perturb other induced fields. In other words, charges on the dislocation loop could significantly affect the traditional dislocation-induced stress/strain, electric displacement, and polarization fields in piezoelectric bimaterials. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

Free