The Influence of Adsorbates on the Interfacial Properties of Fe3O4(001)
EMSL Project ID
41390
Abstract
Magnetite (Fe3O4) currently attracts much attention from the spintronics research community because it is a rare example of a room temperature half-metal. However, the most important Fe3O4 surfaces are often reconstructed and exhibit different magneto-electronic properties to the bulk. This inevitably leads to spin-flipping and inefficient transport of spin-polarized electrons through the interface into another medium. As a consequence, the half-metallicity predicted by density functional theory calculations has never been experimentally verified, and prototype devices utilizing magnetite electrodes have performed poorly (magnetoresistance < 16 %). In the current proposal, the authors detail experiments that will shed light on the structure-function relationship at the Fe3O4(001) surface. These experiments build upon the recent discovery that saturation of the [sqrt(2) x sqrt(2)]R45degrees reconstructed clean surface with atomic H lifts the reconstruction and induces a semiconductor-metal transition. Complementary density functional theory calculations indicate that the density of states (DOS) observed at the Fermi level is 100 % spin polarized. In order to verify this exciting prediction we have entered into collaboration with a world leading group in spin-resolved photoemission spectroscopy, with measurements scheduled to take place at the SRS in Zurich, Switzerland in August. To successfully conduct these experiments we require high quality thin-film Fe3O4 samples that exhibit high coercivity. Dr. Scott Chambers and his group are the experts at producing such films with several directly related publications in the literature. If successful, this work will demonstrate unambiguously whether Fe3O4 is half-metallic, and show clearly that the magneto-transport properties of Fe3O4 surfaces can be favorably modified via surface engineering.
Project Details
Project type
Limited Scope
Start Date
2010-07-01
End Date
2010-08-04
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members