Crystal geometry of screw dislocation glide in tungsten nanocrystals

A zigzag pattern of low-temperature dislocation glide occurring in tungsten nanocrystals in the intersecting planes $\{110\}$ and $\{211\}$, which belong to the $\langle$111$\rangle$ crystallographic zone, has been revealed using field ion microscopy. It has been shown that cores of 1/2[111] screw dislocations are undissociated within the limits of the resolution of the field ion microscope. It has been found experimentally that surface atoms are displaced into metastable positions in the region of the trace of screw dislocation motion.