A study of grain boundary segregation in Cu-Bi alloys using STEM

Abstract
A V.G. Microscopes' HB5 STEM has been used to study a segregated copper-bismuth alloy. It is shown that the Z contrast mechanism due to Crewe (1970 a, b) is not valid for such crystalline materials. Attempts to use the energy loss spectrometer, with which the microscope is fitted, to detect the bismuth spectrum from the grain boundary region were not successful. However, it was found possible to image regions of bismuth on or near to the surface of the foil using a technique analogous to tilted dark field work in a CTEM.