Abstract
Crystal structure and lattice defects of the Ni-36.8 at% Al martensite have been investigated mainly by transmission electron microscopy. A structure of the martensite determined in the present work has a normal Ll0 type (CuAu I type) structure which is different from a modified Ll0 type (not CuAu I type) structure suggested by Rosen and Goebel. Transformation twins in the martensite have been found on the {111}t⟨112⟩t system. Brief considerations are given to the (111)t[11\bar2]t twinning modes.
