Magneto-elastic coupling model of deformable anisotropic superconductors

¹ Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province, School of Mechanics and Engineering, Southwest Jiaotong University - Chengdu, Sichuan 610031, PRC
² State Key Laboratory of Traction Power, Southwest Jiaotong University - Chengdu, Sichuan 610031, PRC
³ Key Laboratory of Mechanics on Environment and Disaster in Western China, The Ministry of Education of China Lanzhou, Gansu 730000, PRC
⁴ Department of Mechanics and Engineering Science, College of Civil Engineering and Mechanics, Lanzhou University Lanzhou, Gansu 730000, PRC

^(a) yingxuli@swjtu.edu.cn (corresponding author)

Received: 11 April 2017
Accepted: 8 June 2017

Abstract

We develop a magneto-elastic (ME) coupling model for the interaction between the vortex lattice and crystal elasticity. The anisotropies in superconductivity and elasticity are simultaneously included in the GL theory frame. Under this consideration, the expression of the free energy unifies the different forms of the classical results. Concerning the ME effect on the magnetization, the theory can give a satisfying description for the field dependence of magnetization near the upper critical field. The contribution of the ME interaction to the magnetization is comparable to the vortex-lattice energy, in materials with relatively strong pressure dependence of the critical temperature. While the magnetization components along different vortex frame axes are strain dependent, the magnetization ratio is independent of the ME interaction. It is stressed that the GL description of the magnetization ratio is applicable only if the applied field moderately close to the upper critical field.