Materials Optimization of the Magnonic Bandgap in Two-Dimensional Bi-Component Magnonic Crystal Waveguides

We present the results of micromagnetic study of magnonic band structures for exchange spin waves propagating in two-dimensional magnonic crystal waveguides. The studied waveguides are in the form of a regular square lattice array of square dots of a ferromagnetic material embedded in a matrix of another ferromagnetic material. Large magnonic bandgaps with widths of tens of GHz are observed. The bandgaps are also studied as a function of in-plane applied magnetic field, and the width of the square dots. The widths of the first three bandgaps are dependent on the material configurations of the waveguides, but are independent of applied field strength.