Ion-induced solid solution and ordered compound formation in Au/Cu bilayers

Abstract

Ion mixing of Au/Cu bilayers has been investigated using He ion backscattering, x-ray diffraction, and transmission electron diffraction techniques. When Au/Cu bilayers are subjected to Ar or Xe ion irradiation at doses of about 1016 ions/cm2 at room temperature, Cu is completely mixed with Au to form a substitutional solid solution with a graded composition. There was no evidence for the presence of crystal compounds. The formation of ordered compounds is achieved either by the mixing of Au/Cu bilayers with Ar ions at 200 °C or by a He ion irradiation of the mixed layers at 60 °C. Similar results have been observed when the mixed samples were subjected to heat treatment at 350 °C. The observations indicate that the phase formation by ion mixing is related to the atomic mobility at the target temperature during implantation.