Magnetic properties of Co-doped TiO2 anatase nanopowders

TL;DR

This study investigates how oxygen vacancies influence ferromagnetism in Co-doped TiO2 nanopowders, revealing that vacancies, not Co clustering, are key to magnetic order.

Contribution

It demonstrates that oxygen vacancies are essential for ferromagnetism in Co-doped TiO2, challenging the idea that Co clustering is necessary for magnetic properties.

Findings

Oxygen vacancies promote long-range ferromagnetic order.

Co clustering is not required for ferromagnetism.

The magnetic properties depend on defect chemistry, not just doping.

Abstract

This letter reports on the magnetic properties of Ti1-xCoxO2 anatase phase nanopowders with different Co contents. It is shown that oxygen vacancies play a fundamental role in promoting the long-range ferromagnetic order in the material studied, in addition to the transition-metal doping. Furthermore, the results allow ruling out the premise of a strict connection between Co clustering and the ferromagnetism observed in the Co:TiO2 anatase system.