COMPUTER-SIMULATION OF SWITCHING IN STONER-WOHLFARTH COLLOIDS

We have developed a method for the inclusion of transverse magnetizati on into a computer simulation of a magnetic ink, a colloidal suspensio n of acicular particles. Previous simulations have assumed a fixed lon gitudinal magnetic moment. We determine the magnetization (assumed uni form) by minimising the Stoner-Wohlfarth energy, so the moment can poi nt in any direction relative to the particle axis. The particle-magnet ization changes and particle rotations occurring during a hysteresis l oop will be shown in the form of a video. This method can be used to s imulate particle orientation during the magnetic-tape coating process.