Annihilation process of periodic antiphase boundaries in Cu₃Pt studied with time dependent Ginzburg Landau model

Kinetics of the annihilation process of periodic antiphase boundaries in a Cu₃Pt alloy has been studied by computer-simulation and transmission electron microscope observation. The kinetic equation was derived from a general equation for the free energy of the system where the ordering and disordering undergo congruently. The excess free energy due to ordering was expressed by a Ginzburg-Landau type expansion, and the boundary energy was assumed to be proportional to the second derivatives of S_r and S_r ², where S_r is the local degree of order at the position r in the system. The simulation was carried out for the annihilation process of flat antiphase boundaries which were arranged periodically, and the characteristic patterns of antiphase boundaries observed with an electron microscope were reproduced successfully.