Room-temperature ferromagnetism in the mixtures of the TiO2 and Co3O4 powders

Abstract

We report here the observation of ferromagnetism (FM) at 300 K in mixtures of TiO2 and Co3O4 powders despite the antiferromagnetic and diamagnetic character of both oxides respectively. The ferromagnetic behavior is found in the early stages of reaction and only for TiO2 in anatase structure; no FM is found for identical samples prepared with rutile-TiO2. Optical spectroscopy and X-ray absorption spectra confirm a surface reduction of octahedral Co+3->Co+2 in the mixtures which is in the origin of the observed magnetism

17 pages, 8 figures

References in corpus (3)

• Magnetic effects at the interface between nonmagnetic oxides
• Sources of experimental errors in the observation of nanoscale magnetism
• Insights into the room temperature magnetism of ZnO/Co3O4 mixtures