恒磁场作用下压磁/压电半导体复合圆柱壳的耦合响应分析

本文针对由压磁材料和压电半导体材料组成的无限长复合圆柱壳结构，理论研究了其在径向恒磁场作用下结构内的多场耦合力学响应问题。为解析求解方便，文中分别采用单向耦合法和线性全耦合法，导出复合圆柱壳内位移场、电场、载流子等物理量的解析表达式。利用导出的解析表达式，数值分析了磁场大小和半导体层厚度比对结构内电势、电场和载流子的影响。计算结果表明：磁场和厚度比均可用来有效调控半导体层内的电学量，复合圆柱壳结构的厚度比有一个最优区间。

Analysis of Multi-field Coupling Responses of Piezomagnetic/Piezoelectric Semiconductor Cylindrical Shell under a Constant Magnetic Field

Piezoelectric semiconductors (PSs) simultaneously possess piezoelectricity and semiconducting properties. The polarization electric field resulted from piezoelectricity has a mechanically tuning effect on the transport behavior of charges in PSs. Such a phenomenon is called the piezotronic effect. With the exception of mechanical approach, one may use the magnetic field to control the piezotronic effect in piezoelectric semiconductors. It is a remote-controlled approach. In this paper, we propose a composite piezoelectric semiconductor cylindrical shell consisting of piezomagnetic and piezoelectric semiconductor layers. A polarization electric field is produced in the composite PS cylindrical shell under a magnetic field through the magnetoelectric coupling effect, and thus the magnetic field has a tuning effect on the piezotronic behavior of the composite PS cylindrical shell. We carry out an analysis on an infinite composite PS cylindrical shell under a constant radial magnetic field. The considered problem belongs to a plane strain problem, and all physical fields in the composite shell are only dependent on the radial position. To obtain the analytical solution and make a comparison, we employ the one-way coupled method and the linear fully-coupled method in this paper. The one-way coupled method neglects the effect of free charges on the polarization electric field. For the linear fully-coupled method, we assume that charges in the PS layer have a small perturbation, and thus the nonlinear drift current term can be linearized. We present analytical expressions of the physical fields in the composite PS shell including the displacement, the electric potential, and the carrier concentration. The influences of magnetic field as well as the thickness ratio between the PS layer and the shell on the piezotronic coupling effect in the composite PS shell are studied. The numerical results show that the magnetic field and the thickness ratio play an important role in tuning the piezotronic effect of the piezoelectric semiconductor layer. At the same time, it also provides a theoretical guidance for the design of piezoelectric semiconductor devices.