Cu-Ti surface-layer mixing by ion-beam modification techniques

摘要

The modification of a titanium substrate by copper ions has been performed in a versatile ion source by alternating ion deposition with ion implantation. As indicated by the experimental results, the mixing efficiency for the Cu-Ti system is greatly sensitive to the ion-treatment mode. The mixing efficiency was examined by Auger electron spectroscopy depth profiling. In the alpha-IBAD mode (the implantation pulse precedes the deposition pulse) the mixing efficiency is noticeably smaller than under beta-IBAD treatment (the implantation pulse follows the deposition pulse). To explain the observed difference in Cu-Ti mixing, the "hot" single layer model based on the thermodynamic approach is proposed. Transmission electron microscopy investigations of the Cu-Ti mixed layer revealed numerous Cu2Ti and Cu4Ti particles 50-100 nm in size. Different quantities of defects around these particles after the alpha-IBAD and beta-IBAD treatments support the "hot" single layer model. The results obtained show the versatile ion source to be a promising tool for the production of deeply mixed metal layers and studies of the ion-mixing mechanism. (C) 1998 Elsevier Science S.A. [References: 21]