Micromagnetism of advanced hard magnetic materials

The continuum theory of micromagnetism has been found to be a rather effective tool to describe magnetic states and magnetization processes. In this paper some rigorous micromagnetic results obtained for characteristic magnetic properties of nanocrystalline hard magnetic materials will be outlined and their application to the development of outstanding magnetic materials will be discussed. In particular the role of exchange coupled composite systems will be considered and the effects of the microstructure will be investigated. Furthermore, the deteriorating effects of magnetically softened surface regions, the depinning and pinning of domain walls at phase boundaries, the remanence exchange enhancing effects and the depinning fields of domain walls of composite particles in the case of high-density recording systems will be discussed.