Thermal Switching Distribution of FePt Grains Through Atomistic Simulation

We have studied through atomistic simulation the switching distribution of FePt grains subject to a declining temperature by evaluating the switching probability at different time delays. It is found that smaller cooling rates and larger field angles, field amplitudes, and damping constants are favorable to more deterministic switching, which can be interpreted as less magnetic recording jitter: the temperature difference during switching of grains is identified as the dominant factor. In particular, the damping-induced lag between spin temperature and lattice temperature has been shown and analyzed. The results are compared with those produced by alternate simulation techniques and the underlying physical mechanisms are discussed.