Magneto-Optical Spectra in Fe(xML)/Au(xML) Artificially Ordered Superlattices.

Abstract

The spectra of the magneto-optical Kerr effect and optical constants were measured in artificially ordered superlattices consisting of 1 to 5 monoatomic layers of Fe and Au. The Kerr rotation spectra showed a prominent structure around 4 eV, which undergoes a shift with layer thickness, the spectral features being quite different from those calculated by the virtual optical constant method which assumes that the superlattice is composed of pure metallic layers. This result suggests the formation of a new ordered alloy with a period extending up to 5 mololayers, which do not exist in the binary phase diagram of thermal equilibrium. The magneto-optical structure around 4 eV is attributed to the Au 5d → Fe 3d transition, on the basis of results of the energy band calculation.