AVS 49th International Symposium
    Magnetic Interfaces and Nanostructures Tuesday Sessions
       Session MI+EL+SC-TuM

Paper MI+EL+SC-TuM3
Co@sub x@Ti@sub 1-x@O@sub 2@ Anatase Heteroepitaxy on Si(001)

Tuesday, November 5, 2002, 9:00 am, Room C-205

Session: Ferromagnetic Semiconductors
Presenter: T. Droubay, Pacific Northwest National Laboratory
Authors: T. Droubay, Pacific Northwest National Laboratory
A.C. Tuan, University of Washington
S.A. Chambers, Pacific Northwest National Laboratory
Correspondent: Click to Email
With a Curie temperature above 700K, high remanence, and respectable coercivity, Co-doped TiO@sub 2@ anatase (Co@sub x@Ti@sub 1-x@O@sub 2@) is one of the more magnetically robust dilute magnetic semiconductor (DMS) materials currently under investigation. The future of this material for near-term device use as a spin injector requires deposition on and compatibility with traditional semiconductors such as silicon. Successful growth of crystalline oxides on silicon without oxidizing the underlying substrate is a formidable challenge. Our goal in this work is to grow epitaxial Co@sub x@Ti@sub 1-x@O@sub 2@ on Si(001) by using a suitable template layer, and then determine the resulting magnetic and electronic properties. We have previously shown that polycrystalline Co@sub x@Ti@sub 1-x@O@sub 2@ grown on Si(001) with its native oxide is ferromagnetic at room temperature. We are now working on Co@sub x@Ti@sub 1-x@O@sub 2@ heteroepitaxy on Si(001) using an ultrathin epitaxial SrTiO@sub 3@ buffer layer to prevent formation of titanium silicide and SiO@sub 2@ at the interface that result from a thermodynamic instability. An added benefit of the SrTiO@sub 3@ buffer layer is to generate a nearly zero conduction band offset to Si, which is essential for efficient n-type spin injection. A detailed analysis of the growth and properties of this heteroepitaxial system will be presented.