SPIN-VALVE EFFECTS IN NICKEL SILICON/NICKEL JUNCTIONS/

We report on fabrication and characterization of a planar spin-valve d evice which has two sets of interdigited nanoscale Ni fingers as two e lectrodes in Schottky contact with Si. The finger width is 75 nm for o ne set and 150 nm for the other. A large length-to-width ratio of the fingers results in a single domain magnetization and a sharp magnetore sistance (MR) response. The switching field of the finger is determine d by the finger width and spacing due to magnetostatic interaction. MR measurements reveal spin-valve effects in the Ni/Si/Ni junctions with MR changes of 0.3 similar to 0.6 % at room temperature. The effects a re discussed within a spin-valve model.