Synthesis of nanocrystalline multiphase titanium oxycarbide (TiCxOy) thin films by UNU/ICTP and NX2 plasma focus devices

Nanocrystalline multiphase titanium oxycarbide (TiCxOy) thin films composed of TiC2, TiO0.325, Ti2O3 and graphitic carbon have been deposited on titanium substrates, using energetic carbon ions delivered by the UNU/ICTP and the NX2 plasma focus devices operated at different repetition rates. X-ray diffraction (XRD) patterns of the nanocomposite films reveal the relative transformation of various oxide and carbide phases accompanied by the suppression of the TiC2 phase when the energy flux of the ion beam and the repetition rate are increased. A field emission scanning electron microscope (FESEM) with an energy dispersive X-ray spectroscopy (EDS) attachment reveals a non-porous microcrack-free nanocrystalline granular surface morphology of the composite films with uniform carbon distribution. X-ray photoelectron spectroscopy (XPS) confirms the formation of oxycarbides (TiCxOy) along with significant carbon adsorbate. Raman studies of the films also verify the relative phase transformation in the TiCxOy nanocomposite by tuning the deposition parameters. The Vickers microhardness of the sample surface is improved more than 400%.