Materials properties of ion beam sputtered Ti-Cu-Pd-Zr thin film metallic glasses

Ti40Cu36Pd14Zr10 (at.%) thin film metallic glasses (TFMG) of 1 μm thickness were ion beam sputtered on to glass, Si (100) wafer and commercially pure titanium (CP Ti). The Ti-based TFMG are thermally stable with a large super cooled liquid region (Tx) of 49.3 °C. XPS and Auger electron spectroscopy (AES) analyses revealed the presence of titanium, copper, zirconium and palladium ions on surface of the films. Ion scattering spectroscopy (ISS) was used to characterize the chemical composition of surface monolayer which indicated a significant level of oxygen on the top surface of the film. X-ray diffraction and TEM indicated an amorphous microstructure of the film. The STEM mapping of the films was quite homogenous and no chemical segregation was discernible in the maps. EDAX showed a slight difference in the composition of the films with respect to sputtering target. Amorphous films with atomically smooth surfaces of roughness in the order of (Ra) 0.l6 nm with the nanohardness of 7.7 GPa and Young's modulus of 106 GPa were observed. The sputtered specimen had superior corrosion resistance in simulated body fluid (SBF). The electro catalytic activity of Ti40Cu36Pd14Zr10 showed a sign of borohydride oxidation in 1 M KOH. The MTT assay using L929 fibroblast cells revealed the non-cytotoxic nature of the coating.