Micromagnetic study of dynamic switching constant in longitudinal thin film media

Dynamic switching time in longitudinal thin film media is studied by numeri cal simulation. An exponential head field with various rise times is assume d. A linear relation (with slope S-w) to correlate the inverse of switching time and the maximum reverse field is found to apply only for rise times l arger than 0.3 ns. The switching constant S-w increases with increasing ris e time, decreasing damping constant, and increasing intergranular exchange. A wide range of S-w, from about 250 to about 3500 Oe ns, is found for rise times between 0.05 and 1 ns. (C) 2000 American Institute of Physics. [S002 1-8979(00)83108-4].