AVS 53rd International Symposium
    Electronic Materials and Processing Wednesday Sessions
       Session EM+MI-WeA

Paper EM+MI-WeA7
Characteristics of Ti@sub 1-x@Co@sub x@O@sub 2@ Thin Films Deposited by MOCVD

Wednesday, November 15, 2006, 4:00 pm, Room 2003

Session: Magnetic Semiconductors
Presenter: A. McClure, Montana State University
Authors: A. McClure, Montana State University
A. Kayani, Montana State University
M. Liberati, Montana State University
J. Dvorak, Montana State University
R.J. Smith, Montana State University
Y.U. Idzerda, Montana State University
E. Arenholz, Lawrence Berkeley National Laboratory
Correspondent: Click to Email
Polycrystalline anatase thin films of Ti@sub 1-x@Co@sub x@O@sub 2@ were prepared on TiO@sub 2@ (50nm)/Si (111) substrates using liquid delivery metal organic chemical vapor deposition (MOCVD). This growth technique allows for the arbitrary variation of the Co concentration. The precursors for these growths were titanium isopropoxide and Co(TMHD)@sub 3@ dissolved in tetrahydrofuran. These films were characterized by X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) to determine the phase of the TiO@sub 2@ host, the Co valency, and the presence of Co clusters. Film thicknesses and Co dopant concentrations were determined from Rutherford backscattering (RBS). A vibrating sample magnetometer (VSM) revealed room temperature ferromagnetism, allowing for a determination of the moment per Co atom vs. Co concentration. I will discuss these results in the context of the bound magnetic polaron model. Recent work@footnote 1@ suggests that this model may only need oxygen vacancies and ferromagnetism may occur with nonmagnetic doping. Our experimental results on Pt:TiO@sub 2@ and its lack of ferromagnetism will also be presented. @FootnoteText@ @footnote 1@Osorio-Guillén, J., Lany, S., Barabash, S. V. and Zunger, A., Phys. Rev. Lett., 96, 107203 (2006).