Effects of Fe doping on the optical and magnetic properties of TiO2 films deposited on Si substrates by a sol–gel route
- 288 Downloads
Fe-doped TiO2 films were deposited on Si(100) substrates by a sol–gel technique. X-ray diffraction measurements show that all the films contain both anatase and rutile phases, and Fe doping promotes the anatase–rutile transformation of TiO2 films. The optical constants of the films were attained by tackling spectroscopic ellipsometry data. With increasing Fe content, the refractive indices n values at 2 eV photon energy first increases, then decreases, and finally increases again, and the optical band gap of the films sharply reduces from 3.60 to 3.30 eV. These results may be not only related to Fe contents but also to the phase composition changed by Fe doping. In addition, the undoped TiO2 film showed feeble ferromagnetic character. Ferromagnetic behaviors were clearly observed for x = 0.01 Fe-doped TiO2 film. When x > 0.01, the magnetizations of the samples, firstly decrease and then increase with the increment Fe content, which may be due to an anatase-to-rutile junction destroying an F-center bound magnetic polaron.
KeywordsTiO2 Phase transition Magnetic property Optical property
The authors are grateful to Jinzhong Zhang, Shijiang Liu and Ping Yu for the technical support. This work was supported by Postdoctoral Science Foundation of Henan Province (2012021), Foundation of He’nan Educational Committee (14B140022), and the National Natural Science Foundation of China (61306019, 51372069, 60990312 and 61076060).
- 20.Gu JJ, Sun HY, Liu LH, Qi YK, Xu Q (2012) Influence of structural phase transition on Ferromagnetism in Fe-doped TiO2 thin films. Acta Phys Sin 61:017501 (In Chinese)Google Scholar
- 24.Moulder JF, Stickle WF, Sobol PE, Bomben KD (1992) Handbook of X-ray photoelectron spectroscopy, 2nd edn. Perkin Elmer, Eden Prairie, MNGoogle Scholar
- 33.Chu JH, Sher A (2008) Physics and properties of narrow gap semiconductors. Springer, New YorkGoogle Scholar
- 40.Bahadur N, Pasricha R, Govind, Chand S, Kotnala RK (2012) Effect of Ni doping on the microstructure and high Curie temperature ferromagnetism in sol–gel derived titania powders. Mater Chem Phys 133:471–479Google Scholar