Theoretical analysis of longitudinal and perpendicular recording potential

The recording potentials of perpendicular recording with a magnetically soft underlayer and of longitudinal recording are compared theoretically under the constraint of write-ability and thermal stability. In contrast to longitudinal media, it is found that optimized perpendicular media require weak exchange interaction between the grains. It is concluded that the potential of longitudinal recording and perpendicular recording with a pole head is not significantly different. Shielded write heads boost the performance of perpendicular recording by 4 to 5 dB.