AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeP

Paper MI-WeP9
Characterization and Room-temperature Ferromagnetic Properties Of Ti@sub 1-x@Co@sub x@O@sub 2@ Films Prepared by Cobalt Implantation

Wednesday, November 5, 2003, 11:00 am, Room Hall A-C

Session: Poster Session
Presenter: S.P. Wong, Chinese University of Hong Kong
Authors: K.H. Cheng, Chinese University of Hong Kong
K.W. Lo, Chinese University of Hong Kong
C.F. Chow, Chinese University of Hong Kong
Y.W. LAI, Chinese University of Hong Kong
W.M. Tsang, Chinese University of Hong Kong
N. Ke, Chinese University of Hong Kong
W.Y. Cheung, Chinese University of Hong Kong
S.P. Wong, Chinese University of Hong Kong
Correspondent: Click to Email
In this work, TiO@sub 2@ thin films were prepared by RF sputtering onto thermally grown oxide layers on Si substrates. Cobalt implantation was performed using a metal vapor vacuum arc (MEVVA) ion source at an extraction voltage of 65 kV to doses ranging from 1.4x10@super 16@ cm@super -2@ to 1.4x10@super 17@ cm@super -2@. Annealing was performed in vacuum at 600@super o@C for 2h. The cobalt composition and distribution in these implanted Ti@sub 1-x@Co@sub x@O@sub 2@ films was studied using Rutherford backscattering spectrometry. The crystal structures were studied using x-ray diffraction. The optical properties were studied using spectroscopic ellipsometry in the wavelength range from 350 to 700 nm. The magnetic properties were measured by vibrating sample magnetometry. We observed clear room-temperature ferromagnetic properties for all the as-implanted and annealed samples prepared under the above conditions. The measured M@sub S@ values ranged from 0.5 µ@sub B@/Co atom to 2.1 µ@sub B@/Co atom and the coercivity values ranged from 200 Oe to 500 Oe, depending on the Co dose and annealing conditions. The correlation between the optical properties, the magnetic properties and their structures will be discussed. This work is supported in part by the Research Grants Council of Hong Kong SAR (Ref. number: CUHK4216/00E and CUHK4221/00E).