Room temperature magneto-optics of ferromagnetic transition-metal doped ZnO thin films

TL;DR

This study demonstrates room temperature ferromagnetism and significant magneto-optic effects in transition-metal doped ZnO thin films, indicating potential for spintronic applications.

Contribution

It provides evidence that ferromagnetism in doped ZnO is an intrinsic property of the bulk material at room temperature.

Findings

Significant magnetic circular dichroism at room temperature.

Ferromagnetic behavior is almost temperature independent above 150K.

Room temperature hysteretic magneto-optic response observed.

Abstract

Magneto-optic studies of ZnO doped with transition metals Co, Mn, V and Ti indicate a significant magnetic circular dichroism (MCD) at the ZnO band edge at room temperature, together with an associated dispersive Faraday rotation. Similar spectra occur for each dopant which implies that the ferromagnetism is an intrinsic property of the bulk ZnO lattice. At 10 K additional paramagnetic contributions to the MCD are observed, but above about 150K, the magnitude of the MCD signal is dominated by the ferromagnetism and is almost temperature independent. The MCD at the ZnO band edge shows room temperature hysteretic behaviour.