The objective of this research is to demonstrate a new magnetic recording paradigm using current-induced switching, which combines the advantages of patterned media, and the potential for lower manufacturing costs. This will be the first demonstration of single grain recording, and the smallest nanostructures yet investigated for current-induced switching. The approach will use self-assembled nanoparticle arrays as etch masks for patterning thin film multilayers into arrays of single particle bits. A conducting atomic force microscope probe will be used in contact mode to electrically contact individual bits. Low current densities will be used to sense the state of the bit, while high current densities will be used for switching. The noise power spectrum as a function of the applied current will reveal how effectively the spin torque is transferred. Simulations will be used to clarify the underlying physics.
This project will have broader impact in several areas. Two graduate students and several undergraduates will learn state-of-the-art techniques of nanoscale synthesis and fabrication, the use of scanning probe and electron microscopy for nanoscale structural characterization, and high sensitivity nanoscale transport measurement techniques. New science fair projects will be developed and the research of students in the Carnegie Mellon University/Milliones and Reizenstein Middle Schools Physics Concepts program will be supervised. Progress made in scanning probe-based recording, current-induced switching media, and the use of self-assembled structures for low cost, manufacturable nanopatterning will be significant for the magnetic recording industry.
