Transport properties of beta-Ga2O3 Nanoparticles embedded in Nb thin films

TL;DR

This study investigates the transport properties of Nb thin films embedded with beta-Ga2O3 nanoparticles, revealing Kondo-like behavior likely due to magnetic moments from oxygen vacancies, advancing understanding of ferromagnetism in nonmagnetic oxides.

Contribution

It demonstrates the embedding of beta-Ga2O3 nanoparticles in Nb films and analyzes their transport properties, linking magnetic behavior to oxygen vacancies, which is a novel insight.

Findings

Transport behavior resembles a Kondo system

Magnetic moments likely originate from oxygen vacancies

Embedded nanoparticles influence electronic properties

Abstract

The origin of ferromagnetism in nanoparticles of nonmagnetic oxides is an interesting area of research. In the present work, transport properties of niobium thin films, with beta-Ga2O3 nanoparticles embedded within them, are presented. Nanoparticles of beta-Ga2O3 embedded in a Nb matrix were prepared at room temperature by radio frequency co-sputtering technique on Si (100) and glass substrates held at room temperature. The thin films deposited on Si substrates were subjected to Ar annealing at a temperature range of 600-650 C for 1 hour. Films were characterized by X-ray diffraction (XRD), Micro-Raman and elemental identification was performed with an Energy Dispersive X-ray Spectroscopy (EDS). Transport measurements were performed down to liquid helium temperatures by four-probe contact technique, showed characteristics analogous to those observed in the context of a Kondo system. A comparison of the experimental data with the theoretical formalism of Kondo and Hamann is presented. It is suggested that this behavior arises from the existence of magnetic moments associated with the oxygen vacancy defects in the nanoparticles of the nonmagnetic oxide Ga2O3.