Long-range elastic interactions and equilibrium shapes of curved ferroelastic domain walls in crystals

Dislocation-disclination models of ferroelastic domain walls (twin walls) are developed. These models are used to calculate long-range stress fields created by curved walls and to evaluate the associated elastic energy. For two basic domain-wall configurations (corner and kink), the equilibrium trajectories of the walls are analysed by minimizing the total energy of the system, which is the sum of the domain wall self-energy and the elastic energy stored in the surrounding medium. It is shown that, by introducing a characteristic length, it is possible to reveal universal features of domain-wall trajectories in ferroelastic crystals.