Energy surface model of single particle reversal in sub-Stoner-Wohlfarth switching fields

A simple energy surface model is introduced to explain single domain particle switching under sub-Stoner-Wohlfarth fields. The criterion is that if the initial energy exceeds the subsequent energy barrier maximum, then the particle can reverse. Reversal will occur only for small damping constants and short field rise times, so the magnetization dynamics explores a sufficiently large portion of the energy surface. The results are confirmed by micromagnetic analyses and are consistent with both large scale micromagnetic simulation and experimental data. This effect may be utilized for ultrahigh density (1 Tbit/in(2)) and ultrahigh data rate magnetic recording (>2 Gbit/s). (C) 2003 American Institute of Physics.