An overview of our research on vortex states in arrays of cobalt and permalloy dots is presented. At first a description of single-domain and vortex states is given together with a discussion of the dependence of magnetization reversal process on dot size and thickness. We then focus our attention on the vortex nucleation/annihilation process in arrays of closely spaced, interacting dots. Several phenomena are describet, including 1) a fourfold anisoptropy in a square array of circular Co dots, 2) formation of chains of vortices with identical chirality in a square array of Co dots, 3) formation of vortices with alternating chiralities in two-dot chains and in zig-zag chains as well as in a honeycomb array of permalloy dots. We show that a detailed investigation of the internal micromagnetic configurations of the dots by MFM imaging and micromagnetic simulations is necessary to understand these phenomena.
Magnetization reversal and vortex chirality correlation in ferromagnetic dot arrays
Natali M;
2008
Abstract
An overview of our research on vortex states in arrays of cobalt and permalloy dots is presented. At first a description of single-domain and vortex states is given together with a discussion of the dependence of magnetization reversal process on dot size and thickness. We then focus our attention on the vortex nucleation/annihilation process in arrays of closely spaced, interacting dots. Several phenomena are describet, including 1) a fourfold anisoptropy in a square array of circular Co dots, 2) formation of chains of vortices with identical chirality in a square array of Co dots, 3) formation of vortices with alternating chiralities in two-dot chains and in zig-zag chains as well as in a honeycomb array of permalloy dots. We show that a detailed investigation of the internal micromagnetic configurations of the dots by MFM imaging and micromagnetic simulations is necessary to understand these phenomena.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.