{1 0 −1 2} twin nucleation induced by FIB micro-stress in magnesium single crystal

Abstract

In this study, Mg single crystals (99.99% purity) were subjected to focused ion beam (FIB) bombardment perpendicular and parallel to the c-axis of the hexagonal close packed (HCP) lattice respectively. The research results indicate that the {10−12} twin nucleation induced by FIB micro-stress in magnesium single crystal is dependent on the applied ion current and the crystal orientation. The incident Ga+ ions dose increases with ion current, which would enhance the FIB loading micro-stress. And when the FIB incident direction is parallel to the close-packed (0001) plane, there would be more ion-atom interactions during FIB bombardment. Both processing mechanisms could lead to larger precipitate-matrix misfit area and further microstructure damage, which might eventually facilitate {10−12} twin nucleation.