Criteria for High Density Magnetic Recording Media

The traditional criteria regarding the optimization of the important magnetic parameters for high density recording applications usually refer to properties which are derived from the ordinary hysteresis loop--coercivity, squareness, coercive squareness, and switching field distribution. We propose that the important media parameters for high density recording are reflected only in their remanence loops measured in the direction of orientation (remanence coercivity, switching field distribution, and initial remanence slope) and in a direction perpendicular to the direction of orientation (increase in the remanence coercivity from the easy to the hard magnetization directions). The proposed remanence loop parameters are justified on the basis of minimizing self and recording demagnetization in the media, taking into consideration the two-dimensional vectorial nature of the writing head field.