In situ 64Cu Doppler-broadening positron-annihilation methods for elevated temperature study of defect formation in metals

A Doppler-broadening positron-annihilation-spectroscopy experiment that utilizes an in situ 64Cu source for the study of Cu and Cu-containing materials is described. This technique is particularly useful for the investigation of defect structure at elevated temperatures, and the present instrumentation provides reliable results up to about 1000 °C. The method described is applicable to Cu-containing samples with as little as about 0.1 at.% Cu. Results from measurements on a single crystal of elemental Cu are compared with literature results obtained using other positron-annihilation methods and electrical-resistivity studies.