Nonlinear magneto-optical effect in Fe/Au superlattices

K. Sato, S. Mitani, K. Takanashi, H. Fujimori, A. Kirilyuk, A. Petukhov and Th. Rasing
Proc 4th Int. Symp. Phys. Magn. Materials, Sendai, August 25, 1998, J. Magn. Soc. Jpn. 23, [1-2] (1999) 352-353

Nonlinear magneto-optical effects were measured in [Fe(nML)/Au(nML)]N superlattices prepared by MBE on a MgO (100) substrate. Nonlinear magneto-optical effects were measured using Ar+-laser-pumped Ti-sapphire laser (lambda=760 nm) with suitable combination of filters, polarizer-analyzer and photon-counting apparatus. A well-defined four-fold symmetry pattern was observed in the polar plot. Reversal of magnetization results in a reflection of the azimuthal pattern with respect to a certain axis. Such a symmetrical property cannot be understood if only electric dipole terms are taken into account in the analysis. The azimuthal pattern is explained in terms of electric quadrupole terms for non-magnetic contribution and dipole terms for magnetic contribution.
Keywords: nonlinear magneto-optical effect, azimuthal pattern, Fe/Au superlattice, surface, interface, electric quadrupole