Magnetic and structural study of Cu-doped TiO2 thin films

TL;DR

This study investigates the structural and magnetic properties of Cu-doped TiO2 thin films, revealing ferromagnetic-like behavior likely due to CuO segregation and substitution effects, with implications for magnetic material design.

Contribution

It provides new insights into the magnetic behavior of Cu-doped TiO2 thin films and the role of CuO segregation and substitution in their magnetic properties.

Findings

All films exhibit ferromagnetic-like behavior.

Magnetic properties are nearly independent of Cu concentration.

CuO segregation and substitution influence magnetic signals.

Abstract

Transparent pure and Cu-doped (2.5, 5 and 10 at. %) anatase TiO2 thin films were grown by pulsed laser deposition technique on LaAlO3 substrates. The samples were structurally characterized by X-ray absorption spectroscopy and X-ray diffraction. The magnetic properties were measured using a SQUID. All films have a FM-like behaviour. In the case of the Cu-doped samples, the magnetic cycles are almost independent of the Cu concentration. Cu atoms are forming CuO and/or substituting Ti in TiO2. The thermal treatment in air promotes the CuO segregation. Since CuO is antiferromagnetic, the magnetic signals present in the films could be assigned to this Cu substitutionally replacing cations in TiO2.