Computer simulation of switching in Stoner-Wohlfarth colloids

We have developed a method for the inclusion of transverse magnetization into a computer simulation of a magnetic ink, a colloidal suspension of acicular particles. Previous simulations have assumed a fixed longitudinal magnetic moment. We determine the magnetization (assumed uniform) by minimizing the Stoner-Wohlfarth energy, so the moment can point in any direction relative to the particle axis. The particle-magnetization changes and particle rotations occurring during a hysteresis loop will be shown in the form of a video. This method can be used to simulate particle orientation during the magnetic-tape coating process.