Tunnel magnetoresistance and temperature related effects in magnetic tunnel junctions with embedded nanoparticles

TL;DR

This study investigates how temperature affects tunnel magnetoresistance in magnetic tunnel junctions with embedded nanoparticles, using quantum-ballistic and double barrier models to analyze resonant conditions and tunneling mechanisms.

Contribution

It introduces a comprehensive model combining quantum-ballistic and double barrier approaches to explain temperature-dependent TMR effects in nanoparticle-embedded MTJs.

Findings

Resonant TMR conditions are highly sensitive to temperature changes.

Direct tunneling dominates in systems with tunneling thickness up to 6 nm.

Coulomb blockade models are insufficient to explain Kondo-related TMR anomalies.

Abstract

Temperature dependence of the tunnel magnetoresistance (TMR) was calculated in range of the quantum-ballistic model in the magnetic tunnel junctions (MTJs) with embedded nanoparticles (NPs). The electron tunnel transport through NP was simulated in range of double barrier approach, which was integrated into the model of the magnetic point-like contact. The resonant TMR conditions and temperature impact were explored in detail. Moreover, the possible reasons of the temperature induced resonant conditions were discussed in the range of the lead-tunneling cell-lead model near Kondo temperature. We also found that redistribution of the voltage drop becomes crucial in this model. Furthermore, the direct tunneling plays the dominant role and cannot be omitted in the quantum systems with the total tunneling thickness up to 5-6 nm. Hence, Coulomb blockade model cannot explain Kondo-induced TMR anomalies in nanometer-sized tunnel junctions.