Transport in Magnetic Nanoparticles Super-Lattices : Coulomb Blockade, Hysteresis and Magnetic Field Induced Switching

TL;DR

This study investigates magnetotransport in Co-Fe nanoparticle super-lattices, revealing temperature-dependent Coulomb blockade transitions, hysteresis, and magnetic field-induced switching, contributing to understanding nanoscale magnetic and electronic interactions.

Contribution

It introduces a novel magnetic field-induced switching mechanism in nanoparticle super-lattices and characterizes temperature-dependent magnetoresistance behaviors.

Findings

Hysteretic Coulomb blockade transition at low temperatures.

Magnetic field can induce abrupt transition between regimes.

Temperature-dependent magnetoresistance phenomena observed.

Abstract

We report on magnetotransport measurements on millimetric super-lattices of Co-Fe nanoparticles surrounded by an organic layer. At low temperature, the transition between the Coulomb blockade and the conductive regime becomes abrupt and hysteretic. The transition between both regime can be induced by a magnetic field, leading to a novel mechanism of magnetoresistance. Between 1.8 and 10 K, high-field magnetoresistance due to magnetic disorder at the surface of the particles is also observed. Below 1.8 K, this magnetoresistance abruptly collapses and a low-field magnetoresistance is observed.