Wall-wall and kink-kink interactions in ferroelastic materials

Kinks interact with other kinks and antikinks elastically in ferroelastic domain walls and other interfaces in ferroic materials. In thin samples, suitable for transmission electron-microscopy, the interaction is purely dipolar with no indication of monopolar or higher order contributions. Kinks and antikinks attract each other while kink-kink interactions are repulsive. When the kinks are situated in two parallel twin walls, they display the same attraction/repulsion. We argue that this interaction constitutes, part or all, the elusive wall-wall interaction in ferroelastics. The dipolar interactions over distances d between the kinks and between walls decay as 1/d2 when the samples have some nanoscale size. Nanoscale samples bend and tilt when kinks are introduced with typical bent regions of some 1 nm and tilt angles of some 1.2 degrees. Multiple kinks will enhance the effect systematically and bent and modulated twin walls are predicted.

Automated summary

Kinks and antikinks interact with each other elastically in ferroelastic domain walls and interfaces in ferroic materials. The interaction is purely dipolar with no indication of monopolar or higher order contributions, and kinks and antikinks attract each other while kink-kink interactions are repulsive. This interaction is believed to constitute, in part or in whole, the elusive wall-wall interaction in ferroelastics. The dipolar interactions decay as 1/d^2 over distances d between the kinks and between walls when the samples have nanoscale size. Nanoscale samples bend and tilt when kinks are introduced, and multiple kinks enhance the effect systematically, leading to bent and modulated twin walls.