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