Kinetics of twin boundaries of a Ni-Mn-Ga martensite in a magnetic field

The martensite in a Ni2MnGa alloy with two variants of twins is considered as the one-dimensional system of two types of close-packed layers in a tetragonal lattice. Position of layers is described by quasi-spin variables, s(i), which characterize the orientation of tetragonal axis, c, of various twinning variants. Movement of twin boundary (TB) under the magnetic-field influence is considered. The controlling equation for TB jump-like movement is proposed, and computer simulation of movement of single TB and TBs' ensemble is carried out. The elastic stresses impeding both a redistribution of the twinning variants and a growth of the advantageous variant are taken into account.