The influence of superparamagnetism on exchange anisotropy at CoO/[Co/Pd] interfaces

TL;DR

This paper investigates how superparamagnetism affects exchange bias and magnetic anisotropy in [CoO/Co/Pd] multilayers, revealing rapid changes in magnetic properties due to thermal blocking of superparamagnetic clusters.

Contribution

It demonstrates the impact of superparamagnetism on exchange anisotropy and magnetic switching behavior in multilayer systems, a novel insight for magnetic device stability.

Findings

Rapid increase in exchange anisotropy field with thermal blocking

Out-of-plane easy axis switching induced by superparamagnetic effects

Superparamagnetism significantly influences magnetic stability in multilayers

Abstract

Magnetic systems exhibiting exchange bias effect are being considered as materials for applications in data storage devices, sensors and biomedicine. As the size of new mag- netic devices is being continuously reduced, the influence of thermally induced instabilities in magnetic order has to be taken into account during their fabrication process. In this study we show the influence of superparamagnetism on magnetic properties of exchange-biased [CoO/Co/Pd]10 multilayer. We find that the process of progressive thermal blocking of the superparamagnetic clusters causes an unusually fast rise of the exchange anisotropy field and coercivity, and promotes the easy axis switching to out-of-plane direction.