Tunnel Magnetoresistance in Self-Assemblies of Exchange Coupled Core/Shell Nanoparticles

TL;DR

This study demonstrates precise control of tunneling magnetoresistance in self-assembled core/shell nanoparticles by tuning magnetic anisotropy via shell composition, enabling optimized magnetotransport device performance.

Contribution

It introduces a method to control TMR in core/shell nanoparticles through magnetic anisotropy adjustment by shell composition, a novel approach for device optimization.

Findings

TMR can be precisely tuned by adjusting Co$^{2+}$ content.

Different core/shell configurations enable optimization of magnetotransport.

Switching fields are controlled by magnetic anisotropy adjustments.

Abstract

We report the precise control of tunneling magnetoresistance (TMR) in devices of self-assembled core/shell Fe$_3$O$_4$/Co$_{1-x}$Zn$_x$Fe$_2$O$_4$ nanoparticles ($0\leq x\leq 1$). Adjusting the magnetic anisotropy through the content of Co$^{2+}$ in the shell, provides an accurate tool to control the switching field between the bistable states of the TMR. In this way, different combinations of soft/hard and hard/soft core/shell configurations can be envisaged for optimizing devices with the required magnetotransport response.