Dresden 2006 – scientific programme
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HL: Halbleiterphysik
HL 4: New materials
HL 4.8: Talk
Monday, March 27, 2006, 12:00–12:15, BEY 154
Ferromagnetism and magnetic anisotropy in Co-implanted TiO2 — •N. Akdogan1, B. Rameev2,3, L. Dorosinsky4, H. Sozeri4, R. Khaibullin3, B. Aktas 2, L. Tagirov3,5, A. Nefedov1, A. Westphalen1, and H. Zabel1 — 1Institute of Experimental Physics IV, Ruhr-University Bochum, D-44780 Bochum, Germany — 2Gebze Institute of Technology, 41400 Gebze-Kocaeli, Turkey — 3Kazan Physical-Technical Institute of RAS, 420029 Kazan, Russia — 4TUBITAK-UME, PK 54, 41470 Gebze-Kocaeli, Turkey — 5Kazan State University, 420008 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 these materials.
Magnetic anisotropy of cobalt implanted single-crystalline rutile has been studied by means of MOKE and SQUID techniques. We observed for the first time strong angular dependence of the remanent magnetization and coercive field in the plane of the implanted surface: twofold anisotropy for the (100)- and fourfold anisotropy for the (001)-substrate samples. Possible origins of ferromagnetism and anisotropies in single-crystalline TiO2 samples after Co-ion implantation are discussed.
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".