Band gap parameters of one-dimensional bicomponent nanostructured magnonic crystals

We investigate theoretically the lowest-frequency spin waves in one-dimensional periodic arrays of alternating cobalt and permalloy nanostripes to analyze their recently measured first band gap parameters. Based on insights from numerical calculations, we formulate simple equations relating center frequencies and widths of the first band gaps of these magnonic crystals to their geometric and magnetic parameters. Analytical calculations based on these equations accord well with both the measured and the numerically generated size-dependences of the band gap parameters. Our approach permits the easy and convenient evaluation of the band gap parameters of bicomponent magnonic crystals comprising one-dimensional arrays of nanostripes of alternating magnetic materials. (C) 2011 American Institute of Physics. [doi:10.1063/1.3541886]