Thermal energy barrier distribution measurements in perpendicular media

dc demagnetized remanent curves at different applied field time durations have been applied to measure the thermal energy barrier distribution of two sets of perpendicular alloy media. Sharrock's formula is applied at all levels of percentages of magnetization switching. The measured energy barrier distribution width decreases with increasing intergranular exchange coupling and with reducing intergranular magnetostatic interactions. The results agree well with micromagnetic simulations. (C) 2002 American Institute of Physics.