COMPARISON OF THE EFFECTS OF REGULAR AND IRREGULAR PHYSICAL STRUCTUREON THE MAGNETIC MICROSTRUCTURE OF LONGITUDINAL THIN-FILMS

Interaction effects in longitudinal thin films are investigated by com puting delta I curves formed by comparison of the remanence curves usi ng the Wohlfarth relation. Historically, throughout the literature, in terpretation of magnetic microstructures has relied upon visual inspec tion of vector maps representing such configurations. However, in this paper, theoretical techniques are used to analyse the magnetic micros tructures of simulated AC-erased and DC-demagnetised states; these tak e the form of a correlation function and Fourier analysis. The role of physical structure on such interactions is investigated by comparing the simulated curves generated from a system of grains lying on a radi ally isotropic structure with those of a system whose physical structu re forms an hexagonal closed-packed (HCP) lattice. Different degrees o f exchange coupling are considered. Disorder in the microstructure is shown to be responsible for a reduction in the magnitude of positive d elta I values. It will be shown how the degree of cooperative switchin g during the magnetisation process is dependent on the underlying phys ical structure of the systems.