Problem 1. Required for credit. Draw arrows indicating the shear stress that would cause the edge dislocation below to move to the right. Now use blue and red to indicate the shear stresses required to make the screw dislocation in the two directions indicated.

Problem 2.

Required for credit. Calculate a vacancy fraction (fraction of vacant lattice sites) for lead at its melting temperature (600 K). The vacancy formation energy is 0.55 eV.

Burgers vector Edge dislocation line cation ne Burgers vector b f03_04_p989