Thermal Generation of Vacancies from Faulted Loops in Aluminum

Abstract

A thermal generation kinetics from faulted loops in high purity aluminum has been studied by the pulse heating technique and the residual resistance measurement. The average concentration of vacancies generated from the loops exceeds the thermal equilibrium concentration of vacancies at the pulsing temperature, depending on the size of the loop. Such a generation profile is explained by a generation mechanism which is promoted by the line tension of the faulted loop. The characteristic promotive energy ΔE in this process is derived to be 0.018 eV and 0.038 eV for the loops with the average diameter 75 nm and 40 nm, respectively. It is concluded that the significant part of ΔE is due to the elastic energy change of the loop associated with the emission of a vacancy, and that the contribution from the stacking fault to ΔE is small in contrast to the earlier works in aluminum.