Deposition of cadmium (II) oxide-reinforced VP glassy thin films by thermionic vacuum arc (TVA) and structural characterization

The thermionic vacuum arc is an original technique in terms of both the deposition mechanism and the properties of the produced plasma. The thermionic vacuum arc has been used as a method for deposition of thin film since it is an anodic arc discharge of the material to be evaporated into vapors. The resulting material ions fall at the substrate where they form a well-adhesive, free from droplets, high-purity, extremely flat, low-roughness, dense, and good structured layer when the thermal stress of the substrates being coated is low and deposition rate is high. In this study, cadmium oxide-doped vanadium phosphate glass was synthesized by using traditional melt-quenching method prior to deposition. This synthesized glass was first deposited as a glassy thin film via the thermionic vacuum arc process. Due to the thermionic vacuum arc method, the thin film deposition process of CdO-doped vanadium phosphate glass was carried out within a short time of 120 s. On the other hand, structural comparisons were made between the similarities of the deposited glassy thin film and the previously synthesized bulk glass sample. X-ray diffraction analysis showed that the glassy thin film had an amorphous structure similar to the synthesized bulk glass. Structural properties of the CdO-doped vanadium phosphate glassy thin film were determined by using Raman spectrum and scanning electron microscopy images, and the elements in the thin film were discussed with the energy-dispersive X-ray analysis in detail. Finally, transmittance properties of glassy thin film were investigated with surface scanning method.