Effect of thermal fluctuation on read/write properties of longitudinal and perpendicular recording media (abstract)

Abstract

The read/write properties of longitudinal and perpendicular recording media affected by thermal fluctuation has been investigated by computer simulation. The write process was simulated based on the Langevin equation.1 The magnetization distributions resulting from thermal fluctuation after the writing were calculated based on the Monte Carlo method2 to obtain the output signals. The material parameters, Ms=400 emu/cm3, Ku=2×106 erg/cm3, and α=1, were used. No exchange interaction was assumed between particles. The temperature of 300 K was used. The calculation region was 6000 Å×12 000 Å, and the film thickness was 187.5 Å. The particle size was varied from 93.8 to 375.0 Å. Eight cycles of signals were recorded using a ring head (6 Gbit/in.2). Figures 1 and 2 show the effect of in-plane particle size on the signal-to-noise ratio 109 s after the recording for the longitudinal and the perpendicular media, respectively. The ratio increased when the particle size is decreased in both cases, but decreased in the longitudinal media when the particle size is less than 120 Å. The write field H0 (the field center in the gap) was varied from 6000 to 9000 Oe.