Direction of modulation during twin boundary motion

Abstract

To study the change of modulation direction during deformation, two NiMnGa single crystals, one with a five-layered modulated tetragonal structure (5 M) and the other with a seven-layered modulated orthorhombic structure (7 M), were chosen. Synchrotron diffraction experiments show that the modulation takes place on the {1 1 0) plane along the left angle bracket1 1 0] directions. During deformation the c-axis orientation changes by twinning, and with this the direction of modulation obeying the twin relation also changes.