Magnetization-induced optical second harmonic generation from the surface of Co-doped rutile TiO2(110)

• Published in: Surface and interface analysis Vol. 40; no. 13; pp. 1692 - 1695
• Main Authors: Watanabe, R., Yuasa, M., Yahata, Y., Mizutani, G., Suzuki, T., Segawa, Y., Matsumoto, Y., Yamamoto, Y., Koinuma, H.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.12.2008; Wiley
• Subjects: Co/rutile TiO2; Condensed matter: electronic structure, electrical, magnetic, and optical properties; dilute magnetic semiconductors; Exact sciences and technology; hysteresis; Magnetic properties and materials; Magnetic properties of surface, thin films and multilayers; Magnetic semiconductors; magnetization-induced optical second harmonic generation (MSHG); Physics; Studies of specific magnetic materials; Surface magnetism; surface magnetization; Co/rutile TiO2; Second harmonic generation; Inorganic compounds; Magnetization; Surface magnetism; Transition element compounds; Magnetic field effects; Doped materials; Optical harmonic generation; dilute magnetic semiconductors; magnetization-induced optical second harmonic generation (MSHG); Magnetic semiconductors; Ferromagnetism; Cobalt additions; Incidence angle; Titanium oxide; surface magnetization; Surface layers; Hysteresis; X-ray photoelectron spectra
• ISSN: 0142-2421; 1096-9918
• DOI: 10.1002/sia.2907

We have investigated the surface magnetism of 5 at% Co‐doped rutile TiO2(110) using magnetization‐induced optical second harmonic generation (MSHG) in the longitudinal Kerr configuration with the incident beam angle of 4° . MSHG is observed at both 2ħω = 2.33 eV and 2ħω = 4.20 eV. MSH intensity showed a hysteresis as a function of the external magnetic field for the second harmonic photon energy of 2ħω = 4.20 eV at which the absorption length limits the MSHG origin to the surface layer of 10 nm due to the TiO2 bulk. Since 5 at% Co: TiO2(110) is judged to have no metallic Co near the top surface by XPS, the hysteresis is attributed to a carrier‐induced ferromagnetism at the surface of this material. Copyright © 2008 John Wiley & Sons, Ltd.