Influence of rotational speed on structure, mechanical and electrical properties of TiC/GLC composite films

In this work, magnetron sputtering deposition facility was performed to fabricate TiC/graphite-like carbon (denoted as GLC) composite films. The microstructure and element composition of the as-fabricated TiC/GLC composite films were analyzed by field emission scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Moreover, the influence of rotational speeds of specimen holder on microstructure, mechanical, and electrical properties of the as-prepared TiC/GLC composite films were systemically investigated. Results indicate that the microstructures of TiC/GLC composite films experience the transition from layered growth pattern to columnar growth pattern with increasing rotational speed. The transmission electron microscope characterizations show that multilayered microstructure was self-organized in the TiC/GLC composite film deposited at rotational speed of 5 degrees/s. The TiC crystallite embedded in carbon networks composite structure dominates the films with other rotational speeds. The TiC/GLC film with multilayered structure has lower internal stress and higher adhesion to the substrate compared to composite structure. The mechanical and electrical measurement results demonstrate that the nano-hardness and conductivity are enhanced owing to formation of high content of hard and conductive TiC phase embed in the carbon networks nanostructure in TiC/GLC composite films. Meanwhile, the growth mechanisms of TiC/GLC composite films at different rotational speeds are also proposed. The excellently electrical and mechanical properties indicate that the GLC/TiC composite film possesses widespread potential as transducers for biosensors in biology and carbonaceous electrode materials.