4. The following data are provided based upon diffusion in a polycrystal with a grain size of 50m, and a Burgers vector b=.3nm. a) Plot these data on an Arrhenius plot. Given that the two higher temperature points reflect the lattice diffusion process, Find Do and Q(kJ/mol) for the lattice diffusion process. b) Since Qgb is estimated to be about half of QL, estimate a value for Dogb based upon your estimate for Qgb (use definition of Dgb ) c) What is the transition temperature for lattice to grain boundary diffusion, and plot this data point on the graph in part a