Anisotropy of magnetostatic wave group velocities in ferromagnetic waveguides

Abstract

The results of theoretical and experimental study of anisotropic propagation of magnetostatic waves (MSW) in ferromagnetic thin-film microsize waveguides are presented. Electrodynamic model of tangentially magnetized ferromagnetic waveguide is developed. On the base of the model, the main features in rotation of group velocity vector of volume MSW (VMSW) by rotating a wave vector and a vector of an external bias magnetic field relative to the axis of symmetry of the waveguide are demonstrated. It is shown, that a decrease in a width of the waveguide to the micron size leads to non-reciprocal propagation of VMSW and to increase of angular divergence between the phase and group velocities of VMSW. The experimental research of T-shaped ferromagnetic microwaveguide demonstrates the difference in power levels of a signal that is branched in the shoulders of T-shaped waveguide when the bias magnetic field is rotated in the waveguide plane.