Crucial role of interfacial $s−d$ exchange interaction in the temperature dependence of tunnel magnetoresistance

Abstract

The tunnel magnetoresistance (TMR) is one of the most important spintronic phenomena but its reduction at finite temperature is a severe drawback for applications. Here, we reveal a crucial determinant of the drawback, that is, the s-d exchange interaction between conduction s and localized d electrons at interfacial ferromagnetic layers. By calculating the temperature dependence of the TMR ratio in Fe/MgO/Fe(001), we show that the obtained TMR ratio significantly decreases with increasing temperature owing to the spin-flip scattering in the $Δ$1 state induced by the s-d exchange interaction. The material dependence of the coupling constant Jsd is also discussed on the basis of a nonempirical method.

Terumasa Tadano

Researcher of Materials Science

My research interests include development of computational methods and softwares for predicting thermal properties of solids, and application of machine-learning methods to material science study