Thermally induced crystallization of amorphous-titania films

Abstract

Three types of amorphous-titania films prepared by ion- and electron-beam techniques have been annealed thermally. An amorphous-crystalline transformation is found in each of these film types at around 350 °C. Its resulting microcrystalline structure and the exact transition temperature appear to be dictated by the rutile microcrystalline seed present in the as-deposited films under different deposition conditions. An amorphous film with a weak rutile seed crystallizes at a lower temperature into the anatase structure, while a film with a relatively strong rutile base crystallizes into the rutile structure at a somewhat higher temperature. It is demonstrated that Raman spectroscopy is a simple and effective tool for characterization of these submicron-thick amorphous films and for the dynamical study of such a phase transformation. Accompanying this amorphous-crystalline transformation, a two-order increase in elastic light scattering is noted implying optical degradation associated with microcrystalline boundaries. In addition, results of the anatase–rutile transformation at a temperature near 900 °C are presented.

Surface characteristics and bioactivity of oxide films formed by anodic spark oxidation on titanium in different electrolytes

“…However, the naturally formed titanium oxide film is not effective in improving the bioactivity of a titanium implant due to its small thickness. Therefore, oxide films need to be formed intentionally using various techniques such as thermal annealing (Feng Velten et al, 2002;Padma et al, 1988), chemical synthesis (Samuneva et al, 1993;Li and Kangasniemi, 1994), physical vapor deposition (Wu et al, 2006;Hsu et al, 1986), and anodic oxidation (Sul et al, 2002;Schreckenbach et al, 1999;Yang et al, 2004;de Sena et al, 2003).…”

Defect-induced luminescence in Co(II)-doped anatase TiO2 prepared by the sol–gel method

“…It can be prepared as thin film by several methods such as sputtering [7,8], electrochemical synthesis [9] and using the sol-gel technique [10,11]. Titania films can be obtained in crystalline or amorphous phases depending on the way they are prepared and on the thermal treatments after deposition.…”

Osteoconductivity of Anodized Titanium with Controlled Micron-Level Surface Roughness

“…[13][14][15][16][17][18] Therefore, the optimization of the surface properties of TiO 2 coatings is key point to improve the osteoconductivity of implants. There are many types of TiO 2 coating methods for Ti substrates, such as thermal treatment, 19) chemical methods, [20][21][22] physical vapor deposition, 23,24) and anodizing. [25][26][27][28] Among these methods, we chose anodizing as a processing route involving hydroprocessing, as a hydrous environment is similar to the internal environment of the body.…”