Room Temperature Ferromagnetic Semiconductor Rutile Ti1-xCoxO2-\delta Epitaxial Thin Films Grown by Sputtering Method

TL;DR

This study demonstrates the successful growth of room temperature ferromagnetic rutile Ti1-xCoxO2-elta thin films on sapphire substrates using sputtering, showing significant magnetic and magneto-optical properties at ambient conditions.

Contribution

First demonstration of sputter-grown rutile Ti1-xCoxO2-elta epitaxial films exhibiting room temperature ferromagnetism and magneto-optical effects.

Findings

Ferromagnetic behavior observed at room temperature.

Magnetization nearly 3μB/Co, indicating high spin Co2+ state.

Enhanced magneto-optical response in sputtered films.

Abstract

Room temperature ferromagnetic semiconductor rutile Ti1-xCoxO2-\delta (101) epitaxial thin films were grown on r-sapphire substrates by a dc sputtering method. Ferromagnetic magnetization, magnetic circular dichroism, and anomalous Hall effect were clearly observed at room temperature in sputter-grown films for the first time. The magnetization value is nearly as large as 3\mu B/Co that is consistent with the high spin state Co2+ in this compound recently established by spectroscopic methods. Consequently, its originally large magneto-optical response is further enhanced.