Calculations of giant magnetoresistance in Fe/Cr trilayers using layer potentials determined from {\it ab-initio} methods

TL;DR

This study uses ab-initio calculations to determine layer potentials in Fe/Cr trilayers and employs these to analyze the giant magnetoresistance (GMR), revealing the critical role of interface monolayers in GMR behavior.

Contribution

It introduces a method to calculate layer potentials from first principles and applies them to predict GMR ratios, highlighting the influence of interface monolayers.

Findings

GMR oscillates with ferromagnetic layer thickness.

Interface monolayers significantly affect GMR.

Calculated GMR ratios agree with experimental data.

Abstract

The ab initio full-potential linearized augmented plane-wave method explicitly designed for the slab geometry was employed to elucidate the physical origin of the layer potentials for the trilayers nFe/3Cr/nFe(001), where n is the number of Fe monolayers. The thickness of the transition-metal ferromagnet has been ranged from $n=1$ up to n=8 while the spacer thickness was fixed to 3 monolayers. The calculated potentials were inserted in the Fuchs-Sondheimer formalism in order to calculate the giant magnetoresistance (GMR) ratio. The predicted GMR ratio was compared with the experiment and the oscillatory behavior of the GMR as a function of the ferromagnetic layer thickness was discussed in the context of the layer potentials. The reported results confirm that the interface monolayers play a dominant role in the intrinsic GMR.