Magnetic Properties, Electron Paramagnetic Resonance, and Photoelectron Spectroscopy Studies of Nanocrystalline TiO2 Co-Doped with Al and Fe

Electron paramagnetic resonance, X-ray photoelectron spectroscopy, field dependence of magnetization, X-ray diffraction, and transmission electron microscopy are applied for the characterization of Al-doped TiO2 nanopowders with Fe impurities synthesized by the autoclave-assisted hydrothermal method and annealed in vacuum or in hydrogen. The sizes of the TiO2:(Al, Fe) nanoparticles are estimated to be about 10-20 nm. It is proposed that Al ions are presumably placed in the TiO2 lattice in interstitial positions. Moreover, Fe3+ ions can occupy tetrahedral positions of Ti4+ ions as a result of Al-doping. The results suggest that Al-doped TiO2 nanopowders with Fe impurities annealed in vacuum or hydrogen display both intrinsic and extrinsic ferromagnetic properties.

Automated summary

In this study, various characterization techniques were applied to investigate Al-doped TiO2 nanopowders with Fe impurities, synthesized by the autoclave-assisted hydrothermal method and annealed in vacuum or hydrogen. The results suggest that these nanopowders display both intrinsic and extrinsic ferromagnetic properties, with particle sizes estimated to be around 10-20 nm.