Content area
Abstract
Interactive phenomena in thin magnetic films are studied for films used as magnetic recording media. The objective is to understand complicated microscopic scale magnetization configurations and nucleation processes in these films as well as their correlations with the film macroscopic quantities. In the course of this work, a theoretical model was developed based on the polycrystalline nature of the films for the study. The model assumes each crystallite in a film to be single crystal and to be always uniformly magnetized. The Landau-Lifshitz gyromagnetic-damping equation is utilized to describe the magnetization rotation of each grain. The study focuses on the effects of the long-range magnetostatic interaction and the short-range exchange coupling between the crystallites in the films. Both longitudinal and perpendicular films are studied. Formation, motion and annihilation of the magnetization vortices characterize the reversal process of a typical longitudinal film. Magnetization chain-rotation followed incoherent reversal of the magnetic columns in the chain represents the distinctive feature of a nucleation process in a typical CoCr perpendicular film. Macroscopic hysteretic quantities of the films, such as squareness and coercivity, are also studied to correlate the microscopic magnetization behavior. Magnetization configuration in transition regions is studied in detail for longitudinal films.
