Dresden 2006 – scientific programme
Parts | Days | Selection | Search | Downloads | Help
MA: Magnetismus
MA 4: Magnetic Materials I
MA 4.1: Talk
Monday, March 27, 2006, 10:15–10:30, HSZ 401
Observation of two ferromagnetic phases in Co-doped rutile TiO2 — •A. Nefedov1, N. Akdogan1, A Westphalen1, R. Khaibullin2, L. Tagirov2, and H. Zabel1 — 1Institut für Experimentalphysik/Festkörperphysik, Ruhr-Universität Bochum, 44780 Bochum, Germany — 2Kazan Physical-Technical Institute of RAS, 420029 Kazan, Russia
Oxide based diluted magnetic semiconductors have recently attracted considerable attention because of reports of room temperature ferromagnetism in several systems and their projected potential for spintronic devices. However, subsequent reports have raised concerns about the initially suggested intrinsic nature of ferromagnetism in this material.
The magnetic properties of Co-doped TiO2 synthesized by ion implantation with different implantation doses have been studied using MOKE, SQUID and XRMS methods. We observe paramagnetic behaviour for low dose doped sample, but obtain clear ferromagnetic behaviour for intermediate and high dose doped samples. The drastical change of the hysteresis loop shape at the transition from the intermediate to high Coimplantation doses, demonstrating a presence of 2 ferromagnetic phases in Co-doped rutile TiO2, has been observed. Origin of these 2 phases will be discussed during the talk.
This work was partially supported by DFG through SFB 491 and by RFBR through grant no. 04-02-97505. N Akdogan acknowledges a fellowship through the Max-Planck Research School "SurMat".