Parallel-leaky capacitance equivalent circuit model for MgO magnetic tunnel junctions

TL;DR

This paper introduces a parallel-leaky capacitance equivalent circuit model for MgO magnetic tunnel junctions, explaining their magnetic field-dependent capacitance behavior through experimental validation and the Maxwell-Wagner model.

Contribution

It proposes a novel RC parallel network model incorporating leaky capacitance to accurately describe MgO MTJs' capacitance properties under magnetic fields.

Findings

Higher leaky capacitance (Cl) in low TMR junctions.

Capacitive behavior confirmed by Cole-Cole plots.

Model validation with experimental data.

Abstract

The capacitance of MgO based magnetic tunnel junctions (MTJs) has been observed to be magnetic field dependent. We propose an equivalent circuit for the MTJs with a parallel-leaky capacitance (Cl) across the series combination of geometric and interfacial capacitance. The analysis of junctions with different tunneling magnetoresistance values suggests higher Cl for low TMR junctions. Using Cole-Cole plots the capacitive nature of MTJs is manifested. Fitting with Maxwell-Wagner capacitance model validates the RC parallel network model for MTJs and the extracted field dependent parameters match with the experimental values.