Magnetostrictive Fe73Ga27 nanocontacts for low field conductance switching

TL;DR

This study demonstrates that magnetostrictive Fe73Ga27 nanocontacts can reliably switch electrical conductance states at low magnetic fields, with stable operation and potential for remote control in nanotechnology.

Contribution

It introduces a reproducible low-field conductance switching mechanism in Galfenol nanocontacts, showing stable contact behavior and quantifying magnetostriction effects at 10 K.

Findings

Conductance switches between on and off states at 20-30 mT

Stable contact configuration with low hysteresis after cycling

Conductance exhibits exponential tunneling behavior below G0

Abstract

The electrical conductance G of magnetostrictive nanocontacts made from Galfenol Fe73Ga27 can be reproducibly switched between on and off states in a low magnetic field of 20 to 30 mT at 10 K. The switching behavior is in agreement with the magnetic field dependence of the magnetostriction inferred from the magnetization behavior, causing a positive magnetostrictive strain along the magnetic field. The repeated magneticfield cycling leads to a stable contact geometry and to a robust contact configuration with a very low hysteresis of 1 mT between opening and closing the contact due to a training effect. Nonintegral multiples of the conductance quantum G0 observed for G is greater than G0 are attributed to electron backscattering at defect sites in the electrodes near the contact interface. When the contact is closed either mechanically or by magnetic field, the conductance shows an exponential behavior below G0 due to electron tunneling. This allows to estimate the magnetostriction at 10 K. The results demonstrate that such magnetostrictive devices are suitable for the remote control of the conductance by low magnetic fields in future nanotechnology applications.