Ion-beam-assisted sputter deposition of thin oxide films

Corrosion resistance for biomaterial applications of TiO2 films deposited on titanium and stainless steel by ion-beam-assisted sputtering

“…19,20 It seems likely that the porosity originates mainly from defects in the thick outer layer, such as small pores existing between the columnar grains. From this it follows that a two-layer oxide model seems to be physically plausible.…”

“…In the initial stage of the deposition process, some of the substrate elements (Fe, Cr) are ejected from the surface into the growing film due to the bombardment effect of high energy particles, and it may be possible that small amounts of Cr 2 O 3 exist beneath the main TiO 2 film. This atomic-mixing phenomenon at the interface affects the properties of the deposited oxide film 19,20 and the results of electrochemical measurements. When a capacitance measurement method is used, some nonlinearity (smooth bending) has been observed in the Mott-Schottky plot of a thin passive oxide film.…”

“…Recently these oxide films and their surfaces were characterized by different surface analytical techniques. [19][20][21] However, the electrochemical properties and corrosion resistance of the materials need to be clarified. In the present study, the IBASD TiO 2 films on titanium and on stainless steel (SS 316L) exposed to a phosphate-buffered saline (PBS) solution have been investigated using different electrochemical methods:…”

“…Among them, ion-beam-assisted sputtering deposition (IBASD) most successfully has produced a dense and relatively thick TiO 2 film on titanium and stainless steel surfaces. 19,20 This method utilizes three roles of the ion beams: (1) the ion beam sputtering of a target to produce the deposit material, (2) the ion-mixing effect within the film to control the porosity of the film and the interfacial layer, and (3) the chemical reactivity of the assisting ion beam to control the stoichiometry of the deposited film. Recently these oxide films and their surfaces were characterized by different surface analytical techniques.…”

Preparation of a drug-eluting stent using a TiO2 film deposited by plasma enhanced chemical vapour deposition as a drug-combining matrix

“…A TiO 2 film may be coated by various wet processes such as dip-coating, spray-coating, and spin-coating and dry processes such as chemical vapour deposition, PECVD, and ion beam assisted chemical vapor deposition, [29][30][31][32][33][34][35][36][37][38] but dry processes are considered to be more suitable processes than wet processes for the coating of a TiO 2 film onto a stent since the dry processes are one-step processes while the wet processes are multi-step processes requiring at least three steps (preparation of a coating solution, a step for coating, and calcination) 35 and more promising for uniform coating of a thin film. [36][37][38][39][40][41][42][43][44][45] Particularly, TiO 2 thin films coated by PECVD are known to have a better coverage and lower roughness than those coated by other CVD processes. 46 After the deposition, the film was surface-modified with water plasma to introduce hydroxyl groups on the surface so that drug compounds could be chemically grafted to the surface through the formation of ester bonds between hydroxyl groups on the modified TiO 2 film and carboxyl groups in the drug molecules as shown in Scheme 1.…”