This reduction of volume for a given material lowers the energy barrier which stabilized the magnetic domain against rotation of the magnetization vector. At finite temperature this can result in time dependent decay of the magnetization. One can study this process by Monte Carlo techniques. Click on the thumbnail image below to see an animation of thermal magnetization decay. Each arrow represents the magnetization vector of a single grain.
Vectors pointing approximately to the right are green and vectors pointing to the left are magenta.
There are over 2,800 grains with easy axis directions random in the plane. The left hand domain is stabilized by this constant field. Subsequent patterns are relaxed at a constant finite temperature. Each grain undergoes 250 Monte Carlo steps between frames in the animation. In this simulation, each grain is modeled as a single tetrahedral finite element.