Characteristics of magneto-static surface wave propagating in layered ferrimagnetic structure with a slightly absorptive superstrate

The paper describes the theoretical and experimental study on the magneto-static surface wave (MSSW) propagating in a layered ferrimagnetic structure, onto which a slightly lossy material such as an electrolyte is covered. We focus on the propagation characteristics of the MSSW; especially, the attenuation of the MSSW, due to the cover material's conductivity. Using the complete electromagnetic theory, the dispersion characteristics of the MSSW were derived. The theoretical analysis was compared with a preliminary experiment using sodium chloride dissolved in water as a superstrate, the result of which was in good agreement. This indicates the possible application of the considered structure to an electrolyte densitometer using the fact that the conductivity is in proportion to the content of the electrolyte