Abstract
A finite element read/write simulation was performed by solving the Poisson equation for a two-dimensional model of an antiferromagnetically coupled magnetic medium (AFC medium) and a thin-film-head system. The AFC medium is composed of two recording layers and a thin intervening Ru layer. From the simulation of an isolated transition, we found (1) the output waveform at t = 0 s has a shoulders on the tail of the main peak corresponding to the extra transition in the bottom recording layer. However, the shoulder becoms small at around t = 10-7 s, and disappears completely at t = 1010 s, (2) An antiparallel magnetization alignment in a bit is produced by thermal energy as well as a reverse field to write the transition. From the simulation at 423 kFRPI, it was found that (3) an antiparallel magnetization alignment in a bit is established in the write process by a reverse field to write the bit. Furthermore, from thermal stability estimation, we found that (4) the time needed to be an antiparallel magnetization alignment in a bit lengthens with the increase of the bottom layer coercive field Hc and with the decrease of the interlayer antiferromagnetic exchange constant A. (5) The output voltage reduction curves at around t = 1012 s depend greatly on A and Hc. (6) The thermal stability of the AFC medium is improved by an order of magnitude in time scale compared with that of the conventional medium.
