Abstract
The magnetic response of surface plasmon polaritons (SPPs) has the potential to be utilized as a magnetic sensor. To this end, a non-solid solution material (Ag-Co system) was selected for evaluation, as such materials are expected to efficiently excite the SPPs, while also highly increasing the magnetic sensitivity with a single layer. In the Ag-Co non-solid solution film, Ag is a good SPP excitation material, whereas Co is a ferromagnetic material. The excitation and magnetic response of the SPPs in Ag-Co single layer films were investigated by varying the film thickness and wavelength, from which it was found that the optimal characteristics for both were obtained with films 35–50 nm thick. The largest magnetic response of the SPPs, as defined by the ratio of reflectivity change under the applied magnetic field between zero and 400 mT, was determined as ～0.29. The Ag-Co non-solid solution system therefore represents a good material for obtaining a large magnetic response of SPPs.
