XAS study of the local environment of impurities in doped TiO2 thin films

TL;DR

This study uses X-ray Absorption Spectroscopy to analyze how impurities like Co, Ni, Cu, and Zn are incorporated into TiO2 thin films, linking impurity environment to observed room temperature ferromagnetism.

Contribution

It provides detailed local environment characterization of impurities in doped TiO2 films and suggests a correlation with ferromagnetic properties.

Findings

Impurities mainly substitute Ti atoms in TiO2.

Presence of transition metal monoxide clusters cannot be ruled out.

Room temperature ferromagnetism is likely due to metal atoms replacing Ti.

Abstract

In this work we present an X-ray Absorption Spectroscopy characterization of the local environment of the impurity in room temperature ferromagnetic anatase TiO2 thin films doped with Co, Ni, Cu, or Zn, deposited on LaAlO3 substrate by Pulsed Laser Deposition. It was found that there is a considerable amount of impurity atoms substituting Ti in TiO2 anatase, although the presence of metal transition monoxide clusters can not be discarded. From our results we infer that the observed room temperature ferromagnetism of the samples could be assigned to the metal transition atoms replacing Ti in TiO2 anatase.