Micromagnetic Modeling of Spin-Wave Excitations in Corrugated YIG Films

In this paper, we study the features of the spin-wave excitation spectrum in a YIG film with a thickness of 0.4 μm and a magnetization of 1.1 kG corrugated due to the periodic relief of the substrate in the form of grooves with a width of 10 μm and a depth of 0.5 μm, with sloping walls, and a period of 20 μm by micromagnetic modeling. Calculations performed for the orientations of the external magnetic field applied in the film plane along (θ = 0) and across (θ = 90°) grooves show that film shape anisotropy leads to quantization of the spectrum and localization of the spin-wave excitations in various parts of the sample. In this case, the spatial distribution of the magnetization amplitude at frequencies in the spectrum at θ = 90° can be characterized by several spatial scales, differing by orders of magnitude. This is explained by the strong inhomogeneity of the ground state on the walls of the grooves at θ = 90°, which leads to the effective excitation of the short-wave part of the spectrum of spin waves in a periodic structure according to the Schlomann mechanism.