Twin boundaries in trained 10M Ni-Mn-Ga single crystals

The arrangement of twin boundaries in trained 10M Ni-Mn-Ga single crystals was investigated by electron backscatter diffraction (EBSD) in a scanning electron microscope. Precise monoclinic structure data including direction of modulation were used to determine all possible boundaries. Besides type I, II and compound twins typical for monoclinic symmetry, a boundary between two directions of modulation was also detected. Compared to EBSD analysis done with simple tetragonal structure for 10 M Ni-Mn-Ga alloys, a more complex microstructure with new boundaries is revealed.