Strongly suppressed 1/f noise and enhanced magnetoresistance in epitaxial Fe-V/MgO/Fe magnetic tunnel junctions

TL;DR

This study demonstrates that alloying Fe electrodes with V in magnetic tunnel junctions significantly reduces 1/f noise and enhances tunnelling magnetoresistance by improving interface quality and reducing dislocation density.

Contribution

It introduces V doping in Fe electrodes to suppress noise and improve TMR in epitaxial Fe-V/MgO/Fe junctions, a novel approach for noise reduction and performance enhancement.

Findings

V doping reduces 1/f noise by nearly 2 orders of magnitude.

Enhanced TMR observed with V alloying due to reduced interface mismatch.

Suppressed noise linked to lower dislocation density and misfit strain.

Abstract

Alloying Fe electrodes with V, through reduced FeV/MgO interface mismatch in epitaxial magnetic tunnel junctions with MgO barriers, notably suppresses both nonmagnetic (parallel) and magnetic (antiparallel) state 1/f noise and enhances tunnelling magnetoresistance (TMR). A comparative study of the room temperature electron transport and low frequency noise in Fe1-xVx/MgO/Fe and Fe/MgO/Fe1-xVx MTJs with 0 <= x <= 0.25 reveals that V doping of the bottom electrode for x < 0.1 reduces in nearly 2 orders of magnitude the normalized nonmagnetic and magnetic 1/f noise. We attribute the enhanced TMR and suppressed 1/f noise to strongly reduced misfit and dislocation density.