Current-induced phase transition in ballistic Ni nanocontacts

TL;DR

This paper reports the experimental observation of a local phase transition from ferromagnetic to paramagnetic in ballistic nickel nanocontacts, influenced by contact size and bias voltage, supported by a theoretical model of local heating effects.

Contribution

It provides the first experimental evidence of current-induced phase transition in ballistic Ni nanocontacts and offers a theoretical explanation based on local heating and electron energy relaxation.

Findings

Phase transition occurs at higher bias voltages for smaller contacts.

Experimental data aligns well with the proposed heating-based theory.

Contact size reduction influences the bias voltage threshold for phase transition.

Abstract

Local phase transition from ferromagnetic to paramagnetic state in the region of the ballistic Ni nanocontacts (NCs) has been experimentally observed. We found that contact size reduction leads to an increase in the bias voltage at which the local phase transition occurs. Presented theoretical interpretation of this phenomena takes into the account the specificity of the local heating of the ballistic NC and describes the electron's energy relaxation dependences on the applied voltage. The experimental data are in good qualitative and quantitative agreement with the theory proposed.