Thermionic Vacuum Arc—A Versatile Technology for Thin Film Deposition and Its Applications

Abstract

This review summarizes the more-than-25-years of development of the so-called thermionic vacuum arc (TVA). TVA is an anodic arc discharge in vapors of the material to be deposited; the energy for its melting is delivered by means of a focused electron beam. The resulting material ions fall at the substrate where they form a well-adhesive layer; the ion energy is controllable. The deposited layers are, as a rule, free from droplets typical for cathodic arc deposition systems and the thermal stress of the substrates being coated is low. TVA is especially suitable for processing refractory metals, e.g., carbon or tungsten, however, in the course of time, various useful applications of this system originated. They include layers for fusion application, hard coatings, low-friction coatings, biomedical-applicable films, materials for optoelectronics, and for solid-state batteries. Apart from the diagnostic of the film properties, also the diagnostic of the TVA discharge itself as well as of the by TVA generated plasma was performed. The research and application of the TVA proceeds in broad international collaboration. At present, the TVA technology has found its firm place among the different procedures for thin film deposition.

Efficient Removal of Methylene Blue and Ciprofloxacin from Aqueous Solution Using Flower-like, Nanostructured ZnO Coating under UV Irradiation

“…Briefly, TVA discharge takes place between two electrodes (anode and cathode), in the vapours of the anode material, vapours that are produced under the intense electron bombardment. An overview of TVA operation principle and applications is given by Vladoiu et al in a recent review [48]. Usually, the discharge cathode consists of a loop-shaped tungsten filament, surrounded by a Wehnelt cylinder used to focus thermo-electrons, while the anode is usually shaped as a crucible (cylindrical shaped), made from materials with high melting point (W, C, TiB), which contains the material to be evaporated (small pieces of Zn, in this case).…”

Experimental Wear Behavior Analysis of Coated Spindle Hook Teeth under Real Harvesting Work Conditions

“…The scanning position is shown in Figure 3 e. The scanning results are presented in Figure 3 f,g. The element composition at Points 1 and 2 is mostly oxygen and iron, with a small amount of sodium, potassium, and chlorine, indicating that the substance at Points 1 and 2 is an iron oxidation product [ 23 , 38 , 39 , 40 ]. After the coating on the surface of the hook tooth wears and fails, the substrate is exposed to air, and the surface of the substrate exhibits oxidized wear, accelerating the wear failure of the hook tooth substrate [ 41 , 42 , 43 ].…”

Synthesis of Lithium Phosphorus Oxynitride (LiPON) Thin Films by Li3PO4 Anodic Evaporation in Nitrogen Plasma of a Low-Pressure Arc Discharge

“…For example, when an electron beam evaporated Cu in a low-pressure gas (He), an increase in the proportion of Cu vapors over 10% led to a sharp drop in the electron temperature of the plasma (from 2.5 to 0.4 eV) and an increase in plasma concentration [32]. It is also known that the method anodic evaporation in a vacuum arc is capable of providing a high degree of ionization of metal vapors [33]. The high degree of vapor ionization during anodic evaporation of Al (up to 80%), achieved by magnetic compression of the arc column on the melt surface, ensured a decrease in the crystallization temperature of α-Al 2 O 3 film [34].…”