Plasmon resonance studies of iron coated gold films with and without an applied magnetic field

Abstract

Surface plasmon excitations can result from the absorption of light incident on gold films. Adding a ferromagnetic metal, in our case iron, allows the surface plasmon resonance peak energy to be manipulated not only by the free electrons present in metals, but by an external magnetic field as well. Surface plasmon resonance is being used by devices found in industry, however manipulations of the surface plasmon resonance peak energy condition need further studies. Two experimental results are reported in this paper based on thin films of iron on gold/chromium, one based on the thickness of iron and the other with an application of a large 4000 Gauss DC magnetic field. Both of these changes result in a shift in the peak energy of the surface plasmon.