Basic design concepts for perpendicular magnetic recording-from viewpoints of high writing ability and resolution

At the beginning of the research into perpendicular magnetic recording about 30 years ago, through many experiments, the authors found out several basic principles for realizing its potential. These are still useful for the design of a head and medium system for perpendicular magnetic recording. To realize the so-called “Tera-bit storage”, the recording layer of a medium which consists of small diameter and high Ku fine magnetic grains must be written by a single-pole head possessing a higher writing ability and a sharper field gradient than the current heads. In this paper, “how to generate a strong and sharp perpendicular field from a single-pole writing head” is described. In particular, two key points are presented; the first is energizing methods for the main pole of a single-pole head and the second is a method for effectively utilizing of the head-medium magneto-static interaction.