  We numerically study the thermal stability properties of computer memory
storage realized by a magnetic ellipse. In the case of practical magnetic
random-access memory devices, the bit can form a spin texture during switching
events. To study the energy barrier for thermally-induced switching, we develop
a variational procedure to force the bit to traverse a smooth path through
configuration space between the points of stability. We identify textured
configurations realizing domain-wall propagation, which may have an energy
barrier less than that of the corresponding monodomain model. We contrast the
emergence of such micromagnetic effects in thermal versus field-induced
switching.
