Asymmetry of anion and cation vacancy migration enthalpies in III-V compound semiconductors: Role of the kinetic energy

In separate publications we have, from a variety of considerations, identified the activation enthalpies for migration by nearest-neighbor hopping, Hm, of vacancies in InP as Hm(VIn)=0.3 eV and Hm(VP)=1.2 eV. These are in the ratio of the masses of the P and In atoms that actually move when VIns and VPs hop to nearest-neighbor sites. Here we argue that this is evidence for the validity of the kinetic interpretation of Hm and the ballistic model of vacancy migration. Indeed, the empirical values are in quantitative agreement with the predictions of the ballistic model. Excellent agreement is also found for VMg migration in MgO. We extrapolate this result to predict that high-temperature values for interstitial migration in Si and other tetrahedral semiconductors will also be dominated by a kinetic-energy term and far larger than low-temperature values are known to be. © 1985 The American Physical Society.