Modification of the Structure, Phase Composition, and Mechanical Properties of the Ti–C60–Ti Films Implanted with 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 ions/cm2) after annealing in vacuum at a temperature of 570 K (3 h) are studied by atomic force microscopy, X-ray diffraction, and nanoindentation. The films are synthesized by resistive evaporation in vacuum. Titanium and C60 fullerite layers are sequentially deposited onto a substrate of oxidized single crystal silicon. It is established that intense diffusion of titanium into the fullerite layer occurs 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. Implantation of titanium– fullerite–titanium films with boron ions leads to mixing of titanium and fullerite layers, while the size of structural components increases from 40 nm to 80 nm compared to nonimplanted films. Auger electron spectroscopy reveals that ion implantation gives rise to an increase in the atomic fraction of oxygen in the films and the formation of a new phase of TixOyC60, which leads to an increase in the nanohardness of the mixed layers. The implanted Ti–C60–Ti films are annealed in vacuum at T = 570 K for t = 3 h. Thermal annealing gives rise to recrystallization of the fullerite phase and intense growth of a new phase of TixOyC60 with improved mechanical properties.