Linear density dependence of thermal decay in longitudinal recording

We present experimental and theoretical data on the signal decay of recordings measured at various densities. In contrast to expectations, the signal decay does not generally increase with increasing linear density; rather, it peaks at a surprisingly low density. Using a nondestructive spin-stand technique, we determined the energy barrier as well as the anisotropy field distribution. These experimental data are used in a self-consistent recording model that accounts for thermal activation effects at writing as well as at storage. We found that the record process inevitably induces phase shifts in the recorded pattern that lead to the observed decay behavior.