Quenching and annealing of lattice vacancies in pure lead

Lead (99.9999% pure by weight) wires were quenched.in a low temperature (s35 K), low-pressure (10-100 bars absolute) helium atmosphere. Initial quench rates were between 1 and 3X10 4 °C/sec. The formation energy for a lattice vacancy was determined to be 0.54+0.02 eV and the resistivity for one atomic percent vacancies was found to be 2.8+0.1 po-cm. Annealing studies indicated that the vacancy behavior of lead is similar to other face-centered-cubic metals. Two annealing stages are observed. One stage near 170 K is attributed to the migration of vacancy type defects to clusters. A second stage at 330 K is associated with the dissolution of vacancy clusters and vacancy loops. Slope change measurements made at 140 K and 150 K indicate a divacancy migration energy of 0.45±0.04 eVe Anneals at 269 K and 322 K indicate a strong influence from impurities. A divacancy binding energy of 0.23+0.03eV is found. Good agreement with defect equilibrium concentration measurements and self-diffusion data is achieved.U of I OnlyThesi