Modification of the structural and phase composition and mechanical properties of the Ti – C60 – Ti films implanted by boron ions

Abstract

Changes in the structure, phase composition, and mechanical properties of Ti – C60 – Ti films implanted with B+ ions (E = 80 keV, D = 1 1016 ion/cm2) after annealing in vacuum at temperature 570 K (3 hours) were studied by the methods of atomic force microscopy, X-ray diffraction and nanoindentation. The films were obtained by resistive evaporation in vacuum. Layers of titanium and C60 fullerite were sequentially deposited onto a substrate of oxidized single-crystal silicon. It has been established that during the condensation of the fullerite layer (h = 250 nm) on the underlying titanium layer (h = 120 nm), and then the titanium layer (h = 150 nm) on the fullerite layer, intense diffusion of titanium into the fullerite layer occurs. Implantation of titanium-fullerite-titanium films with boron ions leads to mixing of titanium and fullerite layers, while the size of structural elements increases in comparison with non-implanted films from 40 nm to 80 nm. Auger electron spectroscopy revealed that ion implantation results in an increase in the atomic fraction of oxygen in the films and the formation of a new TixOyC60 phase, which leads to an increase in the nanohardness of the mixed layers. The implanted Ti – C60 – Ti films were annealed in vacuum at T= 570 K for t = 3 h. Thermal annealing results in recrystallization of the fullerite phase and intensive growth of a new TixOyC60 phase with improved mechanical properties.