Spin Wave Excitation and Propagation Properties in a Permalloy Film

Abstract

Spin wave excitation and propagation properties in a permalloy were investigated using a vector network analyzer for the magnetostatic surface wave (MSSW) and magnetostatic backward volume wave (MSBVW) configurations. In the MSSW configuration, the excitation and transmission spectra show many peaks. They originate at the distance of antenna lines of the coplanar waveguide, and the waveguide design is important for selecting the excitation and transmission wave vectors of the spin wave. The attenuation length of the MSSW was estimated to be 7.1 µm, and the group velocity of the MSSW with a wave number of 0.26 µm-1 was estimated to be about 8.6 µm/ns for an external magnetic field of 20 mT. In the MSBVW configuration, however, the excitation spin wave spectrum shows a single peak, since many quantized peaks overlap. A transmission signal with a single peak was also detected, but this could be an artifact such as an induced current.