Highly anisotropic nano-magnets Rosa A. Lukaszew, University of Toledo, DMR 0355171

1. Highly anisotropic nano-magnetsRosa A. Lukaszew, University of Toledo, DMR 0355171 Motivation Kerr magnetometry evidenced the perpendicular anisotropy that arises when the L1o phase is formed in FePd Films. Nano-magnets made with L1o binary alloys are of interest because they exhibit extremely large magnetic anisotropy and thus can withstand the super-paramagnetic limit. Polar Kerr Ordered Phase Transverse Kerr MFM images of L1o FePd films The images show domain-size configuration that scales with film thickness. The optimum temperature for substantial formation of the L1o orderedphaseduringgrowth of FePd films was monitored with XRD. The ordered phase formed at 450 oC. Additional experiments were carried out to study L1onano-structures in FePt films which exhibit even higher magnetic anisotropy than FePd. 30 nm 15 nm 5 nm

2. Highly anisotropic nano-magnetsRosa A. Lukaszew, University of Toledo, DMR 0355171 Broad Impact: • Education: 3 graduate and 5 undergraduate students have been involved in this research. • Outreach: Two successful outreach programs were organized for the Toledo community: Saturday Mornings with Science and Physics Summer Camp. • Publications during this period: • ‘Real time structural modification of epitaxial FePt thin films under x-ray rapid thermal annealing using undulator radiation’, J. R. Skuza, R. A. Lukaszew, E. M. Dufresne, D. A. Walko, C. Clavero, A. Cebollada, C. N. Cionca and R. Clarke, Appl. Phys. Lett.90, 251901 (2007). • 'Temperature and thickness dependence at the onset of perpendicular magnetic anisotropy in FePd thin films sputtered on MgO (001) ', C. Clavero, J. M. García-Martín, J. L. Costa Krämer, G. Armelles, A. Cebollada, Y. Huttel, R. A. Lukaszew, and A. J. Kellock, Phys. Rev. B73, 174405 (2006). • 'Atomistic Modeling of Alloy Ordering After Fe Deposition and Annealing on Pt(111) ', G. Bozzolo, R. A. Lukaszew and J. E. Garces, Appl. Phys. Lett.88, 011915 (2006). • Sample growth and structural characterization were performed in the PI’s laboratory and also in collaboration with the Madrid Institute of Microelectronics (IMM), Madrid, Spain. Two proposals, one for rapid thermal annealing (XRTA) and characterization of L1o FePt films and another to study induced magnetization in the Pd capping layer in FePd samples were approved and the experiments were successfully carried out at the Advanced Photon Source (APS), Argonne National Laboratory. Aspects of these experiments have been presented at various national and international meetings. • Ion-implantation studies to induce highly ordered FePt L1o crystallites on epitaxial Pt films were carried out at the University of Toledo. The implanted samples have been annealed and real time XRD was carried out. Analysis of this data is in progress.