Magnetic semiconducting anatase TiO2-delta grown on (100) LaAlO3 having magnetic order up to 880 K

作者:Yoon Soack Dae*; Chen Yajie; Yang Aria; Goodrich Trevor L; Zuo Xu; Ziemer Katherine; Vittoria Carmine; Harris Vincent G
来源:Journal of Magnetism and Magnetic Materials, 2007, 309(2): 171-175.
DOI:10.1016/j.jmmm.2006.05.014

摘要

We demonstrate a semiconducting, material, TiO2-delta, with magnetism up to 880K, without the introduction of magnetic ions. The magnetism in these films stems from the controlled introduction of anion defects from both the film-substrate interface as well as processing under a deficient oxygen atmosphere. First-principle band structure calculations indicate that the exchange between Ti cations mediated by an oxygen anion is positive, i.e., ferromagnetic, whereas the exchange between cations via a vacancy is negative, i.e., ferrimagnetic. It is likely that both the mechanisms are active in this system. This represents a new and promising approach in the search for room-temperature magnetic semiconductors.