Micromagnetic modeling of spin-wave excitations in corrugated YIG films

Particularities of the spin-wave spectrum in YIG film with the thickness of 0.4 $\mu$m and magnetization of 1.1 kG that was corrugated due to the periodical substrate relief in the form of grooves having width of 10 $\mu$m, depth of 0.5 $\mu$m, sloped walls and period of 20 $\mu$m were studied with the help of micromagnetic modelling. Calculations were carried out for the external magnetic field applied along ($\theta$ = 0) and across ($\theta$ = 90$^{\circ}$) the grooves in the film plane, and showed that the anisotropy from the film form caused the spectrum quantization and localization of spin-wave excitations in the different parts of the sample. Besides that, spacial distribution of magnetization amplitude at fixed frequencies in the spectrum for $\theta$ = 90$^{\circ}$ can be characterized by several spacial scales that differ by orders. This is explained by the strong inhomogeneity of equilibrium state at grooves' walls for $\theta$ = 90$^{\circ}$ that leads to the effective excitation of short-wave part of the spin-wave spectrum in the periodical structure by Schlömann mechanism.