It was recalled that the nm-scale thickness and energy of twin boundaries governed the martensitic twin structure and its dynamics which were responsible for the super-elasticity of shape-memory alloys. Here, a method which had been developed for investigating twin-wall structures in ferroelectric crystals was applied to a shape memory alloy crystal. The fitting of simulated displacement fields to atomic force microscopic measurements permitted the extraction of the thickness of type-I twin boundaries in Cu-Al-Ni. Furthermore, a relationship between the twin-boundary thickness and energy was developed and used to evaluating the twin boundary energy.

Investigation of Twin Boundary Thickness and Energy in CuAlNi Shape Memory Alloy. D.Shilo, A.Mendelovich, V.Novák: Applied Physics Letters, 2007, 90[19], 193113