Peierls stress for <110>{001} mixed dislocation in SrTiO_3 within framework of constrained path approximation  

作　　者：Xiaozhi Wu Shaofeng Wang RuipingLiu 

机构地区：[1]Institute for Structure and Function, Chongqing University, 400044 Chongqing, China

出　　处：《Acta Mechanica Sinica》2010年第3期425-432,共8页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(10774196);Science Foundation Project of CQ CSTC(2006BB4156);Chongqing University Postgraduates' Science and Innovation Fund(200707A1A0030240)

摘　　要：The core structure of （110）{001} mixed disloca- tion in perovskite SrTiO3 is investigated with the modified two-dimensional Peierls-Nabarro dislocation equation con- sidering the discreteness effect of crystals. The results show that the core structure of mixed dislocation is independent of the unstable energy in the （100） direction, but closely related to the unstable energy in the （110） direction which is the direction of total Burgers vector of mixed dislocation. Furthermore, the ratio of edge displacement to screw one nearly equals to the tangent of dislocation angle for differ- ent unstable energies in the （110） direction. Thus, the con- strained path approximation is effective for the （110）{001} mixed dislocation in SrTiO3 and two-dimensional equation can degenerate into one-dimensional equation that is only related to the dislocation angle. The Peierls stress for （110） {001 } dislocations can be expediently obtained with the one-dimensional equation and the predictive values for edge, mixed and screw dislocations are 0.17, 0.22 and 0.46 GPa, respectively.The core structure of （110）{001} mixed disloca- tion in perovskite SrTiO3 is investigated with the modified two-dimensional Peierls-Nabarro dislocation equation con- sidering the discreteness effect of crystals. The results show that the core structure of mixed dislocation is independent of the unstable energy in the （100） direction, but closely related to the unstable energy in the （110） direction which is the direction of total Burgers vector of mixed dislocation. Furthermore, the ratio of edge displacement to screw one nearly equals to the tangent of dislocation angle for differ- ent unstable energies in the （110） direction. Thus, the con- strained path approximation is effective for the （110）{001} mixed dislocation in SrTiO3 and two-dimensional equation can degenerate into one-dimensional equation that is only related to the dislocation angle. The Peierls stress for （110） {001 } dislocations can be expediently obtained with the one-dimensional equation and the predictive values for edge, mixed and screw dislocations are 0.17, 0.22 and 0.46 GPa, respectively.

关 键 词：Peierls stress - Mixed dislocation SRTIO3 

分 类 号：O484.1[理学—固体物理] TQ174.756[理学—物理]