IN-SITU CU-64 DOPPLER-BROADENING POSITRON-ANNIHILATION METHODS FOR ELEVATED-TEMPERATURE STUDY OF DEFECT FORMATION IN METALS

Doppler-broadening positron-annihilation-spectroscopy experiment that utilizes an in situ Cu-64 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 p resent instrumentation provides reliable results up to about 1000 degr ees C. The method described is applicable to Cu-containing samples wit h as little as about 0.1 at.% Cu. Results from measurements on a singl e crystal of elemental Cu are compared with literature results obtaine d using other positron-annihilation methods and electrical-resistivity studies.