Orientation dependence of screw dislocation motion in b.c.c. transition metals

A tight-binding type electronic theory is used to calculate the Peierls stress of the screw dislocation in b.c.c. transition metals. The repulsive core-core interaction energies are simulated by Born-Mayer type potentials as well as the modified Born-Mayer potentials. It is shown that there are essential differences in the orientation dependence of the screw dislocation motion among the transition metals, in agreement with experiments.