AVS 61st International Symposium & Exhibition
    2D Materials Focus Topic Tuesday Sessions
       Session 2D+AS+HI+MC+NS+PS+SP+SS-TuA

Paper 2D+AS+HI+MC+NS+PS+SP+SS-TuA8
Surface Characterization of Metal Oxide Layers Grown on CVD Graphene and Spin Precession Measurements

Tuesday, November 11, 2014, 4:40 pm, Room 310

Session: 2D Materials Characterization including Microscopy and Spectroscopy 
Presenter: Akitomo Matsubayashi, University at Albany-SUNY
Authors: A. Matsubayashi, University at Albany-SUNY
W. Nolting, University of Albany-SUNY
D. Sinha, University at Albany-SUNY
A. Jayanthinarasimham, University of Albany-SUNY
J.U. Lee, University of Albany-SUNY
V.P. LaBella, University at Albany-SUNY
Correspondent: Click to Email
Ultra thin metal oxide films grown on graphene can be utilized as dielectric barriers between metals and graphene to help isolate a metal contact from the graphene channel for device applications. This is particularly important for graphene based spintronic devices as tunnel barriers between the ferromagnetic metal as a spin injector and graphene have been known to increase the spin relaxation time measured utilizing non-local detection technique of spin precession by avoiding the conductivity mismatch problem. However, simply depositing metal oxide layers such as aluminum oxide on graphene results in non-uniform film lowering the quality of the interface barrier. We will present a systematic study of aluminum oxide layers grown on CVD graphene under ultra-high vacuum conditions with and without titanium seed layers. The aluminum oxide layers with the 0.2 nm titanium seed layers showed reduced surface roughness. The chemical and structural composition determined by XPS will be also presented that shows full oxidation of the aluminum and partial oxidation of the titanium. The I-V characteristic study performed to electrically evaluate the metal oxide and the preliminary results of non-local spin precession measurements will be also addressed.