| AVS 60th International Symposium and Exhibition | |
| Magnetic Interfaces and Nanostructures | Tuesday Sessions |
| Session MI+EM-TuM |
| Session: | Spintronics and Magnetoelectrics |
| Presenter: | K. Yang, The College of William and Mary |
| Authors: | K. Yang, The College of William and Mary V. Kryutyanskiy, Moscow State University, Russian Federation I. Kolmychek, Moscow State University, Russian Federation T. Murzina, Moscow State University, Russian Federation R.A. Lukaszew, The College of William and Mary |
| Correspondent: | Click to Email |
Magnetic materials in nanometer scale typically exhibit significant different magnetic and magnetic-optical properties compared to bulk materials. Composite thin films with magnetic metal clusters embedded in a non-magnetic metal matrix offer a tailored self-assembled nanoscale platform to investigate magneto-optical and magneto-transport properties and possible correlations between them in constrained geometries. The magnetic clusters size as well as the overall composite thin film thickness can be tailored via adequate deposition conditions to achieve a viable nanocluster binary system. We have previously shown that Au/Co/Au trilayers as well as Au-Co nanocomposite thin films exhibit strong enhancement of the linear magneto-optical properties under surface plasmon polariton excitation. [1] Based on these previous results on linear optics measurements, we investigate now the non-linear optical properties such as second harmonic generation (SHG) as well as the magneto-transport properties in Au-Co nanocomposite thin films. Optical SHG is a sensitive probe of surface and buried interfaces due to inversion symmetry breaking at the interfaces of center-symmetric materials which allows probing structural and morphological properties near interfaces. Here we observe a non-monotonous dependence of the SHG magnetic contrast on the cobalt content in Au-Co films, which reveals a sharp increase close to the transition from a granular-like type structure with Co clusters embedded in gold, to an interconnected composite structure when percolation of the cobalt clusters sets in. We also find a SHG enhancement for Co fractional content of 0.35, within the granular structure regime, that can be associated with localized surface plasmon resonance as well as with local field enhancement in an inhomogeneous composite. Furthermore, the magneto-transport measurement (i.e. the magneto-resistance, MR) properties of the Au-Co composite thin films follow similar trend as a function of Co content as the non-linear SHG magnetic contrast before percolation and dramatically deviate once percolation sets in. Thus, our correlated SHG-MR results in Au-Co nanocomposite thin films with varying Co content will be presented and discussed.
[1]. K. Yang et al. Journal of Applied Physics 107, 103924 (2010); C. Clavero, K. Yang, J. R. Skuza, and R. A. Lukaszew, Optics Express 18, 7743 (2010).