Question- a) Explain what is the driving force for the establishment of an equilibrium point defect concentration in metals outside of irradiation. For a solid with a vacancy formation energy of 1 e V, calculate the equilibrium vacancy concentration as a function of temperature in the range of room temperature to 1000 C and plot in an Arrhenius plot (log Cv in the y axis and 1/T (in degree K) in the x axis).
b) If the steady state vacancy concentration under irradiation is given by?
Where k is the displacement rate (dpa/s), Dv is the vacancy diffusion coefficient (cm2/s), and ?d is the dislocation density (cm-2), calculate at which temperature would the thermal equilibrium value calculated in part a) be comparable to the steady state vacancy concentration? Assume the vacancy migration energy is 1.2 eV, the displacement rate is 10-7 dpa/s and the dislocation density is 1010 cm-2 Assume a=0.3 nm, Z=8 and the vibration frequency equal to 1013 Hz.
Illustrate structures to prove your interpretation.