COLLECTIVE EFFECTS ACCOMPANYING MAGNETIZATION OF 2-DIMENSIONAL LATTICES OF NANOSIZE MAGNETIC PARTICLES

Collective effects arising in a two-dimensional lattice of nanosize ma gnetic particles as a result of the dipole interparticle interaction a re investigated by Hall magnetometry. The experimental system consists of 10(5) permalloy particles having a diameter of similar to 40 nm an d a height of similar to 40 nm and forming a lattice with a rectangula r unit cell (90 nm X 180 nm). We attribute the characteristic features observed in the magnetization curves to quasi-one-dimensionality of t he experimental lattice of particles and to the formation of solitons in chains of dipoles. (C) 1998 American Institute of Physics. [S0021-3 640(98)00818-4]