Non-Classical Twin Boundaries

We use the topological model to analyze recent experimental observations of non-classical twins in Ni2MnGa and demonstrate that glissile disconnections cannot form in these boundaries. Our model describes the formation of misfit-free non-classical TBs through the interaction of active disconnections of two compound twins, i.e., the twin is not formed by one simple shear but, instead, is a metastable configuration without long-range strain resulting from the impingement of two compound twins.