Thermal magnetization reversal in arrays of nanoparticles

摘要: The results of large-scale simulations investigating the dynamics magnetization reversal in arrays single-domain nanomagnets after a rapid applied field at nonzero temperature are presented. numerical micromagnetic approach uses Landau–Lifshitz–Gilbert equation including contributions from thermal fluctuations and long-range dipole–dipole demagnetizing effects implemented using fast-multipole expansion. individual model 9 nm×9 nm×150 nm iron pillars similar to those fabricated on surface with scanning tunneling microscope assisted chemical vapor deposition [S. Wirth et al., J. Appl. Phys. 85, 5249 (1999)]. Nanomagnets oriented perpendicular spaced 300 apart linear considered. is always surface. When magnitude less than coercive value, about 2000 Oe for an nanomagnet, can only occur by t...