  This article presents theoretical results for the dynamic response of
periodically surface-modulated ferromagnetic thin films. For such system, the
role of the periodic dipolar field induced by the modulation is addressed by
using the plane-wave method. By controlling the geometry of the modulated
volumes within the film, the frequency modes and spatial profiles of spin waves
can be manipulated. The angular dependence of the frequency band-gaps unveils
the influence of both dynamic and static magnetic charges, which reside in the
edges of the etching periodic zones, and it is stablished that band-gap widths
created by static magnetic charges are broader than the one created by dynamic
magnetic charges. To corroborate the validity of the model, the theoretical
results are compared with ferromagnetic resonance simulations, where a very
good agreement is achieved between both methods. The theoretical model allows
for a detailed understanding of the physics underlying these kind of systems,
thereby providing an outlook to potential applications associated with magnonic
crystals-based devices.
