Which diffusion mechanism do you expect to be faster vacancy

Which diffusion mechanism do you expect to be faster vacancy diffusion or interstitial diffusion? CIRCLE THE BEST ANSWER Vacancy mechanism Interstitial mechanism The mechanism of diffusion is not expected to have a significant effect on rate of diffusion. Briefly explain:

Solution

Interstitial diffusion is faster than vacancy diffusion because:

(1) interstitial atoms, being smaller, are more mobile; and (2) the probability of an empty adjacent interstitial site is
greater than for a vacancy adjacent to a host atom.