Demagnetization due to inverse magnetostriction effects in longitudinal thin film media

Unpredictable mechanical stresses that occur during the operation of hard disk drives can degrade the recorded signal. On the basis of a micromagnetic analysis and the calculated stress field during head-disk impact, inverse magnetostriction effects in longitudinal recording thin film media are considered and demagnetization due to head-disk impact is simulated numerically. Thin film media are modeled as planar hexagonal arrays of hexagonally shaped grains. The computation uses the conjugate gradient algorithm to minimize the variation of the total energy. In particular, the effect of the stress on the relaxation process is investigated. Also the change in the remanent magnetization due to repetitive head-disk impacts is calculated. We obtained results indicating that the effect of the impact stress during dynamic loading is not so significant as to cause data loss during operation for the longitudinal thin film media.<>