The mechanism of AC-biased magnetic recording

The mechanism of ac-biased magnetic recording is directly related to the physical and magnetic properties of the recording medium. A theory has been developed which describes this relationship, both qualitatively and quantitatively. The action of ac bias on a single-domain particle is examined, and the factors determining its remanent state are analyzed. When the analysis is extended to an aggregate of such particles, it is found that the interaction fields created by the particles themselves are responsible for the biased recording mechanism. The transfer characteristic obtained with ac biasing is derived directly from the distribution of interaction fields in the aggregate material.