The formation of nanosized layers on the copper-nickel alloy surface by implantation O$^+$ ions

V. L. Vorobyov, F. Z. Gilmutdinov, P. V. Bykov, V. Ya. Bayankin

Physical-Technical Institute, Ural Branch of the Russian Academy of Sciences, Izhevsk, Russia

Abstract: Formation of chemical and phase compositions, atomic and local atomic structures of surface layers of metallic materials, including nanoscale, with improved mechanical and exploitation properties by different physical or chemical methods, in particular by ion implantation, to be one of the directions of modern science and technology. The processes of forming these layers, the structural mechanisms for their implementation and the nature of change of various properties of metals and alloys by ion irradiation still remain unclear despite the research in this field. The aim of this work is a comparative study of the formation of the composition and chemical structure of nanosized surface layers of copper-nickel Cu$_{50}$Ni$_{50}$ alloy by implantation O$^+$, Ar$^+$ ions and sequential implantation Ar$^+$ and O$^+$ ions in the pulse-periodic regimes. The choice of copper-nickel alloy was determined to view as a model alloy. The copper-nickel alloys find wide application in various branches of modern industry, particularly, in shipbuilding. The implanted ions were selected to be the elements chemical and inert nature, respectively. The accumulation of oxygen atoms in the nanoscale surface layers of copper-nickel alloy after implantation O$^+$ ions has been identified in the paper. The accumulation of oxygen atoms accompany by the simultaneous segregation of nickel atoms. The implantation by Ar$^+$ ions leads to the enrichment near-surface layers of copper atoms and the depletion of nickel atoms. It has been shown that segregated to the near-surface layers of copper atoms under the conditions of implantation Ar$^+$ ions prevent the accumulation of oxygen atoms in near-surface layers by a subsequent implantation O$^+$ ions, what is determined by a weak chemical activity of the oxygen atoms to the copper atoms.

Keywords: ion implantation, X-ray photoelectron spectroscopy, chemical composition, nanosize surface layers.

UDC: 537.534:539.422.24:620.178.152.34