Origin of pseudoelasticity by twinning in D03-type Fe3Ga.

We investigated the process of twin boundary migration to clarify the origin of pseudoelasticity by twinning in D0 3 -type Fe 3 Ga using first-principles calculations. We calculated the energy profile of twin boundary migration and found that although energy barriers appear during twin boundary migration in bcc Fe and bcc Mo, there was no energy barrier for twin boundary migration in D0 3 -type Fe 3 Ga. Analysis of the shear strain at each twin layer revealed that twin boundary migration in D0 3 -type Fe 3 Ga proceeded not in a layer-by-layer fashion but by the sliding of more than two layers that include the twin boundary, which led to the flat energy profile in D0 3 -type Fe 3 Ga. This sliding mechanism originated from shear strain introduced near the twin boundary to accommodate the lattice distortion induced by the difference in the atomic arrangement between the D0 3 matrix and the pseudo twin layers. [ABSTRACT FROM AUTHOR]