Anisotropic magnetic coupling of permalloy micron dots forming a square lattice (original) (raw)

Static magnetic and spin wave properties of square lattices of permalloy micron dots with thicknesses of 500 Å and 1000 Å and with varying dot separations have been investigated. A magnetic fourfold anisotropy was found for the lattice with dot diameters of 1 µm and a dot separation of 0.1 µm. The anisotropy is attributed to an anisotropic dipole-dipole interaction between magnetically unsaturated parts of the dots. The anisotropy strength (order of 10 5 erg/cm 3) decreases with increasing in-plane applied magnetic field.