METHOD OF OPTIMIZING THE THERMAL STABILITY OF MAGNETIC STRUCTURES BY CALCULATING THE TIME DEPENDENCE OF MAGNETIZATION

摘要

The invention can determine the optimum layer thickness of magnetic storage media. The invention eliminates the limitation of current methods by randomly selecting magnetic grains and then, by calculating the flip probability, deciding whether the grain will flip or not, where r is the relaxation time. The time step tm is calculated in such a way that the flip-over probability equals a constant P. Thus, tm is determined by tm, i = -ln (l-Ps) / (1 / r), where Ps (flip-over probability) is an input parameter that defines the flip probability of the selected grain. A recommended range for this parameter are values between 0.001 and 0.5. With a smaller number of Ps, the results become more accurate. However, more computing time is needed. This time step tm, i is calculated for each magnetic grain and stored in a list. The minimum value of this list is used to determine tm. During the simulation, external fields can be applied to the magnetic system, which after some iterations may require recalculation of the time step tm. The result of the thermal demagnetization of the magnetic structure is used to determine the minimum layer thickness necessary to obtain the required thermal stability. This information about the required layer thickness is processed in the sputtering system to produce the required layer.