Ferromagnetism and spin polarized charge carriers in In$_{2}$O$_{3}$ thin films

TL;DR

This study demonstrates room temperature ferromagnetism and significant spin polarization in In$_2$O$_3$ thin films, including Cr-doped variants, suggesting carrier-mediated magnetic behavior in oxide semiconductors.

Contribution

It provides direct measurements of spin polarization in In$_2$O$_3$ films, establishing their ferromagnetic and spin-polarized nature at room temperature.

Findings

Room temperature ferromagnetism in In$_2$O$_3$ and Cr-doped In$_2$O$_3$ films

Approximately 50% spin polarization measured via Point Contact Andreev Reflection

Ferromagnetism likely mediated by charge carriers in oxide semiconductors

Abstract

We present evidence for spin polarized charge carriers in In$_2$O$_3$ films. Both In$_2$O$_3$ and Cr doped In$_2$O$_3$ films exhibit room temperature ferromagnetism after vacuum annealing, with a saturation moment of approximately 0.5 emu/cm$^3$. We used Point Contact Andreev Reflection measurements to directly determine the spin polarization, which was found to be approximately 50$\pm$5% for both compositions. These results are consistent with suggestions that the ferromagnetism observed in certain oxide semiconductors may be carrier mediated.