Interfacial magnetization dynamics of a bi-component magnonic crystal comprising contacting ferromagnetic nanostripes

Abstract

An investigation of the interfacial magnetization dynamics of a magnonic crystal comprising alternating, contacting cobalt and Permalloy nanostripes is reported. Recently measured spin-wave dispersion data of the crystal in its ferromagnetic and antiferromagnetic phases are interpreted in terms of the effective spin pinning at its cobalt-Permalloy interfaces based on generalized Guslienko-Slavin boundary conditions. Calculations using a macroscopic theory well reproduce the experimental data. Numerically generated mode profiles reveal considerable effective pinnings at the interfaces. The obtained pinning parameters have values significantly larger than the values calculated at the lateral edges of individual stripes, suggesting that the strong interfacial coupling, reported in our previous study, contributes significantly to the effective pinning at the interfaces between adjacent stripes.