Magnetoresistance of galfenol-based magnetic tunnel junction

B Gobaut,M Eddrief,G Rossi,M Marangolo,D Krizmancic,S Roddaro,H Rafaqat,G Panaccione,P Torelli,G Vinai,C Castán-Guerrero

doi:10.1063/1.4939019

Abstract

The manipulation of ferromagnetic layer magnetization via electrical pulse is driving an intense research due to the important applications that this result will have on memory devices and sensors. In this study we realized a magnetotunnel junction in which one layer is made of Galfenol (Fe1-xGax) which possesses one of the highest magnetostrictive coefficient known. The multilayer stack has been grown by molecular beam epitaxy and e-beam evaporation. Optical lithography and physical etching have been combined to obtain 20x20 micron sized pillars. The obtained structures show tunneling conductivity across the junction and a tunnel magnetoresistance(TMR) effect of up to 11.5% in amplitude.

Highlights

The effort for controlling the magnetization of ferromagnetic thin films by means of electric pulses has been tremendously intense in recent years.[1,2,3] This research was driven from the great potential applications that such a possibility would open in the domain of magnetic memories and sensors
The obtained structures show tunneling conductivity across the junction and a tunnel magnetoresistance (TMR) effect of up to 11.5% in amplitude
The ideal experiment would be to change the resistive state of a magnetic tunnel junction (MTJ) via the application of an electric pulse

Summary

Introduction

The effort for controlling the magnetization of ferromagnetic thin films by means of electric pulses has been tremendously intense in recent years.[1,2,3] This research was driven from the great potential applications that such a possibility would open in the domain of magnetic memories and sensors. Fe/MgO/Fe heterostructure is known to exhibit a very high magnetoresistance ratio[19] at room temperature, the obtained structure Fe1-xGax/MgO/Fe appears to be ideal to test the coupling between the stress of the magnetostrictive material (Galfenol) and the resistance of the whole junction.

Results

Conclusion