Fig. 7

Phonon dispersion curves for the martensitic-phase structures of the 13 SMAs with stoichiometric composition ratios. The space-group type of the structure is also shown in each panel. The band paths in the Brillouin zones are set based on the space-group type of the structure.⁷⁵ All of the martensitic phases of 13 SMAs do not show any imaginary modes