AVS 49th International Symposium
    Magnetic Interfaces and Nanostructures Monday Sessions
       Session MI+EL-MoM

Paper MI+EL-MoM4
Tunneling Transport Across Reverse Biased Ag/Fe/Ag/GaAs Schottky Barriers

Monday, November 4, 2002, 9:20 am, Room C-205

Session: Spintronic Materials and Hybrid Devices
Presenter: D.A. Hite, National Institute of Standards and Technology
Authors: D.A. Hite, National Institute of Standards and Technology
S.E. Russek, National Institute of Standards and Technology
D. P. Pappas, National Institute of Standards and Technology
Correspondent: Click to Email
Electrical transport characteristics for the epitaxial Ag/Fe/Ag/GaAs(100) system have been studied under various growth conditions. The surfaces and structure of the multilayer were characterized by low energy electron diffraction and angle-resolved Auger electron diffraction at all steps of the fabrication. We have been able to prepare clean, well-ordered, epitaxial multilayers. The ultra-thin Ag buffer layer (~7 atomic layers) was prepared in a manner to create an ultra-thin layer to mediate the growth morphology of the Fe layer, to prevent the undesired intermixing associated with the Fe/GaAs system, and to create a tunneling barrier in reverse bias. In-situ conductance spectroscopy measurements were performed in order to characterize the rate of electron injection into the semiconductor as a function of bias voltage. We find that these multilayer diodes exhibit a reverse bias tunneling effect above 0.6 V. This is significant because it shows that we have been able to overcome the conductivity mismatch problem between the Fe and GaAs using an ultra-smooth, ultra-thin Ag buffer layer. The possibility of using these structures for direct spin injection from the Fe across the Ag/GaAs Schottky barrier will be discussed.