Fabrication and Static Magnetic Properties of Novel One- and Two-Dimensional Bi-Component Magnonic Crystals

We have fabricated using advanced electron beam lithography, periodic arrays of lateral one-dimensional (1-D) and two-dimensional (2-D) bi-component exchange and magnetostatically coupled magnonic crystals (MC) consisting of alternating cobalt (Co) and Permalloy (Py) nanowires (NWs) and nanodots (NDs), lying side by side. For 1-D MCs, the width of the Co NWs is fixed at 160 nm while the width of the Py NWs is varied from 160 to 800 nm. We observed two distinct switching steps corresponding to the reversal of Py and Co NWs in the array, in contrast to single step switching of homogeneous NWs. For 2-D MCs, the diameter of both Co and Py dots were kept constant at 400 nm. We found that strong dipolar fields from neighboring Co dots strongly influence the reversal process of Py dots resulting in the tuneability of vortex nucleation and annihilations fields.