Solute segregation and antiphase boundary motion in a B2 single phase

Solute segregation and antiphase boundary (APB) migration in a B2-ordered single phase were studied using computer simulations based on the microscopic master equations in the point approximation with both first- and second-neighbor pair interactions. It is shown that the degree of segregation at APBs is highly anisotropic; for the particular case of a cylindrical APB along the z-directions, it is found that maximum segregation occurs along the [1 1 0]-direction and is essentially zero along the [1 -1 0]-direction. Despite the strong segregation anisotropy, however, it is demonstrated that the decrease in the square of the radius of the cylindrical antiphase domain in single-phase B2 is linearly proportional to time, t. It is also shown that the mobility of an APB at a given temperature is strongly composition dependent.