Surface Analysis and Structures Spherical Crystals of Very Clean Au, Cu and Au-Cu Alloys Grown from a Drop of Melt

Abstract

Surface impurities on spherical Au and Cu crystals grown from a drop of melt on graphite in UHV were analyzed by Auger electron spectroscopy after the metals had been cleaned by melting resp. roasting in air. Crystals of Au-Cu alloys grown by the same technique show enrichment of the less abundant component.The well known reconstructions Au(001)(5x20) and Au(l 1 l)(23x 1) could not be detected by RHEED and LEED on cleaned Au crystals. But both structures were confirmed on crystals of Au + 45 at ppm Cu. Au(l 10)(1 x2) was present on cleaned and weakly Cu alloyed Au crystals.