Spin glass properties mapped by coercivity in ferromagnet/spin glass bilayers

Nanotechnology. 2019 Mar 22;30(12):125702. doi: 10.1088/1361-6528/aaf9ef. Epub 2018 Dec 19.

Abstract

We report on a study on the spin glass (SG) anisotropy (K SG) and interfacial exchange coupling (J IF) dependent coercivity (H C) at the ferromagnet/SG interface, based on a modified Monte Carlo Metropolis algorithm. It is shown that K SG and J IF are interdependent while taking effect on different magnetic degrees of freedom and different time scales, resulting in complicated H C behaviors. By means of a micromagnetic approximation approach, we analytically explain the H C behaviors with respect to K SG and J IF. The dynamic SG surplus magnetization and the SG spin rotatability at the interface, hard to be detected experimentally, have proven to play crucial roles. This paper elucidates the weak anisotropy dependence of SG magnetic properties, and predicts that the SG features can be tunable at will by precisely controlling the magnetic parameters.