Title :
Micromagnetic Simulation of Thermal Activation Volume in Perpendicular Recording Media With Dispersions of Grain Size
Author :
Igarashi, M. ; Akagi, F. ; Sugita, Y.
Author_Institution :
Central Res. Lab., Hitachi Ltd., Tokyo
Abstract :
The process of thermal switching and thermal activation volume of perpendicular recording media with dispersions of grain size have been analyzed using micromagnetic simulation with Voronoi lattice model. It was found that in media with smaller inter-grain exchange coupling w, almost all grains switch thermally alone, and the average activation volume langVacrang does not depend on the applied DC reverse field significantly. While, in media with larger w, several neighboring grains switched simultaneously and langVacrang increased with increasing reverse field, but not so much. It was also found that langVacrang increased slightly with w until w reached some critical value, beyond which langVacrang increased remarkably with w
Keywords :
grain size; lattice theory; micromagnetics; perpendicular magnetic recording; Voronoi lattice model; grain size dispersion; inter-grain exchange coupling; micromagnetic simulation; perpendicular recording media; thermal activation volume; thermal switching; Gaussian distribution; Grain size; Lattices; Magnetic anisotropy; Magnetostatics; Micromagnetics; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Saturation magnetization; Switches; Activation volume; Voronoi lattice model; grain size dispersion; micromagnetic simulation; perpendicular recording media; thermal switching unit;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2006.878683