TiC crystallite formation and the role of interfacial energies on the composition during the deposition process of TiC/a:C thin films

Abstract

TiC / amorphous carbon (TiC/a:C) nanocomposite thin films were deposited from two targets by direct current (DC) magnetron sputtering system at room temperaure. The film´s composition and morphology were studied in detail by High Resolution Transmission Electron Microscopy (HRTEM), Selected Area Electron Diffraction (SAED), X-ray Photoelectron Spectroscopy (XPS) and Raman Spectroscopy. The sputtering power of carbon target (P C ) was kept at the constant 150 W, while the sputtering power of titanium target (P Ti ) was changed between 5 W and 150 W. Additionally, a C/Ti multilayer was deposited and characterized for comparison. The growth mechanism was derived from the XPS, Raman and HRTEM observations on the grown layer structures and it was completed by a semi-empirical equation for the dependence on the average atomic fraction of Ti. The HRTEM investigations A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT2 confirmed that the first nucleating phase is amorphous carbon due to its lowest surface energy among the possible phases. The second nucleating phase within the amorphous carbon matrix is TiC; its growth is kinetically not limited. The increase of Ti content resulted in larger TiC nanocrystallites and thinner amorphous carbon spacing between the TiC phases shown by HRTEM analysis. The characteristic texture of the crystallite structure was observed in the case of 120 W and 150 W of P Ti . All observation confirmed the two main phases; amorphous carbon + carbide phase. The hcp titanium phase was not formed due to nucleation barrier. The average sputtered composition differs from the average deposited composition due to different nucleation barriers of different phases.

Optimization of C/TiC duplex diffusion barrier coatings for SiC /Ti composites based on interfacial structure evolution exploration

“…Obviously, the TiC crystal grains (~ 20 nm) are noticeably larger than the nanocrystalline (~ 5 nm) TiC grains embedded in the amorphous carbon matrix, which appears to have limited the growth of TiC grains in the RC-TiC coating. The microstructural difference between the two TiCx coatings is strongly dependant on the carbon content of the coating, which is also observed in other reported works[20,22] 8.…”

Mechanical characterization and corrosion behavior of protective TiC/amorphous C nanocomposite coating as surface thin film

“…X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to study and compare the chemical compositions and morphologies of the deposited TiC/a:C protective thin films. XPS has been used to evaluate the chemical composition of the TiC/a:C nanocomposite coatings using an Al anode similarly to our previous experiments [27,34,35] containing the detailed description of this measurement. The XPS signal was collected from a macroscopic 5 × 5 mm area.…”

Application of sputtered ceramic TiC/a:C thin films with different structures by changing the deposition parameters

“…The quantities that can be calculated from the measured intensities are 2-4% which increases with the Ti content of the layer. 32 The mechanical measurements showed that by incorporating a small amount of titanium, that is, approximately 13 at. % into a:C resulted in a softening of the films (Table 1).…”