Strain-induced magnetization change in patterned ferromagnetic nickel nanostructures

Abstract

We report strain-induced coercive field changes in patterned 300 x 100 x 35 nm(3) Ni nanostructures deposited on Si/SiO(2) substrate using the magnetoelastic effect. The coercive field values change as a function of the applied anisotropy strain (similar to 1000 ppm) between 390 and 500 Oe, demonstrating that it is possible to gradually change the coercive field elastically. While the measured changes in coercive field cannot be accurately predicted with simple analytical predictions, fairly good agreement is obtained by using a micromagnetic simulation taking into account the influence of nonuniform strain distribution in the Ni nanostructures. The micromagnetic simulation includes a position dependant strain-induced magnetic anisotropy term that is computed from a finite element mechanical analysis. Therefore, this study experimentally corroborates the requirement to incorporate mechanical analysis into micromagnetic simulation for accurately predicting magnetoelastic effects in patterned ferromagnetic nanostructures. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3592344]