Tuneable vertical hysteresis loop shift in Ni80Fe20/SrRuO3 heterostructures

TL;DR

This paper reports a tunable vertical hysteresis loop shift in Ni80Fe20/SrRuO3 heterostructures, modeled with micromagnetic simulations, and proposes a generalized theory for its control in spintronic applications.

Contribution

It introduces a novel vertical hysteresis shift in Ni80Fe20/SrRuO3 bilayers and develops a generalized model for its tunability based on material parameters.

Findings

Vertical shift reaches 33% at 2 K

Shift depends on film thickness and anisotropy balance

Model closely matches experimental data

Abstract

A novel vertical hysteresis loop shift is observed for a bilayer thin film of Ni80Fe20/SrRuO3 (1:2 thickness ratio) on SrTiO3 substrate, after field cooled through the Curie temperature ~125 K of SrRuO3, whereas no shift is found for zero field cooled measurement. The vertical shift is noticed below ~125 K which increases with decreasing temperature and reaches a maximum of 33% at 2 K. The vertical shift is modelled closely using micromagnetic simulations. It is shown that the amount of vertical shift depends on the competition between the relative thicknesses and the anisotropies of the two films governed by Spring Thickness law and Imperial Law, respectively. We propose a generalized model of vertical shift which is applicable for other material systems, and hence could be informative for use of vertical shift in future spintronic devices.