Influence of nanocrystalline structure and composition on hardness of thin films based on TiO2

Abstract

Abstract:In this work, the influence of Tb-doping on structure, and especially hardness of nanocrystalline TiO 2 thin films, has been described. Thin films were formed by a high-energy reactive magnetron sputtering process in a pure oxygen atmosphere. Undoped TiO 2 -matrix and TiO 2 :Tb (2 at. % and 2.6 at. %) thin films, had rutile structure with crystallite sizes below 10 nm. The high-energy process produces nanocrystalline, homogenous films with a dense and close packed structure, that were confirmed by X-ray diffraction patterns and micrographs from a scanning electron microscope. Investigation of thin film hardness was performed with the aid of a nanoindentation technique. Results of measurements have shown that the hardness of all manufactured nanocrystalline films is above 10 GPa. In the case of undoped TiO 2 matrix, the highest hardness value was obtained (14.3 GPa), while doping with terbium results in hardness decreasing down to 12.7 GPa and 10.8 GPa for TiO 2 :(2 at. % Tb) and TiO 2 :(2.6 at. % Tb) thin films, respectively. Incorporation of terbium into TiO 2 -matrix also allows modification of the elastic properties of the films.

Correlation of Photocatalysis and Photoluminescence Effect in Relation to the Surface Properties of TiO2:Tb Thin Films

“…Broad peaks in the XRD patterns have shown that both thin films had nanocrystalline structure. of crystallites sizes to 6.6 nm; however, the structure was still the rutile [37,39,40]. No diffraction peaks of Tb or Tb-O compounds have been found.…”

“…Titanium dioxide thin films doped with terbium have been deposited by high-energy reactive magnetron sputtering process (HERMS) [36][37][38]. Thin films were deposited in pure oxygen plasma (without argon as a working gas) by sputtering of metallic titanium target.…”