AVS 50th International Symposium
    Magnetic Interfaces and Nanostructures Wednesday Sessions
       Session MI-WeM

Paper MI-WeM8
Current-Triggered Domain Wall Motion in Focused Ion Beam Fabricated Magnetic Nanowires

Wednesday, November 5, 2003, 10:40 am, Room 316

Session: Current-Induced Magnetic Switching and Excitations
Presenter: C.T. Rettner, IBM Almaden Research Center
Authors: C.T. Rettner, IBM Almaden Research Center
M. Tsoi, IBM Almaden Research Center
L. Thomas, IBM Almaden Research Center
S. Parkin, IBM Almaden Research Center
Correspondent: Click to Email
Focused ion beam techniques have been used to pattern NiFe and CoFe thin films into nano-wires to study magnetic domain wall motion triggered by an electric current. We have investigated a variety of shapes, including simple and notched straight lines as well as zigzags and semi-circular shapes. Our scheme begins with a large structure created by deposition of the magnetic material onto SiO2 through a shadow mask. This structure consists of 1 mm pads connected by a 0.1 mm line. The focused ion beam is first used to cut this line with a 11 nA beam leaving just 6 microns of film on the centerline. Next an 11 pA beam is used to roughly form the desired shape in this region, and a 4 pA with ~25 nm resolution is used to add details such as notches and to form the final dimensions. We will discuss our observations of current-triggered domain-wall motion in these structures, including results for motion in zero fields. These results include magneto-resistive measurements and MFM imaging. Finally, we will briefly discuss the results in terms of micro-magnetic simulations for these structures.