Crystal Structure Peculiarities of Martensite in the Ni47Mn42In11 Alloy that Underwent Forward and Reverse Phase Transformations

The martensite structure of the Ni₄₇Mn₄₂In₁₁ alloy has been studied, and crystallographic peculiarities of the structure realized after ten cyclic forward and reverse phase transformations have been shown. Each cycle includes the heating to a temperature corresponding to the existence of austenite and subsequent cooling to cryogenic temperatures. It was found that (107)-twinned martensite crystals can contact not only on the (107¯ ) plane, which, being the symmetry axis for the crystals, is not among the close-packed planes, but also on the (127¯ ) plane, which is among close packed planes but is not the symmetry axis.