An exactly solvable phase transition in an Ising system with a grain boundary

I will consider the effect of a tier of weakened bonds along the center line of a two-dimensional Ising ferromagnet strip as a model of a grain boundary. When an interface traverses such a strip at an angle, a phase transition may be induced which depends on the temperature, the chosen angle and the degree of bond weakening. The phase boundary for this transition may be computed exactly, and the results confirmed by Monte-Carlo study.
I will also discuss and compare the relaxation of such a system to its equilibrium state using continuous time Monte Carlo simulation with Kawasaki dynamics and with a Langevin approach based on a horizontal solid-on-solid approximation to the above system. This reveals a matter transport mechanism confined to the grain boundary.