Surface nanostructuring ofTiO2thin films by high energy ion irradiation

Abstract

The effects of a high ion dose irradiation on TiO 2 thin films under different conditions of temperature and ion nature are discussed. We have shown that anatase TiO 2 thin films irradiated with N + ions at room temperature develop a typical microstructure with mounds and voids open to the surface whereas irradiations at 700 K generate a surface pattern of well-ordered nanorods aligned with the ion beam. The formation of these patterns is caused by the simultaneous effect of ion irradiation near the film surface and a film temperature favoring the structural mobilization of the defective network of the material. To explain these phenomena, a qualitative model has been proposed and further tested by irradiating the TiO 2 thin films with F + and S + ions under different conditions. The obtained results demonstrate that ion irradiation techniques enable the formation of tilted nanorod surface patterns with lengths of about 100 nm on anatase TiO 2 thin films.

Nitrogen Nanobubbles in a-SiOxNy Coatings: Evaluation of Its Physical Properties and Chemical Bonding State by Spatially Resolved Electron Energy-Loss Spectroscopy

“…Similar closed pores microstructures can be found in ion-irradiated or ion-implanted thin films [17][18][19][20][21][22][23] which have been pointed out as fabrication routes for nanostructured materials and surfaces. [19][20][21][22][23][24][25] Generally these microstructures consist in few pores situated at a certain distance from the surface; while with our methodology, highly porous structures with uniform porosity from the substrate to the coatings surface are deposited, in a wide range of thicknesses (from 100 nm to few microns).…”

“…[11][12] However, this approach may also be generalized to allow to study other systems, including nitride materials, and containing cavities filled with molecular nitrogen either formed during synthesis [30][31][35][36] or nanostructuring processes like ion irradiation or implantation. 19,[22][23] Finally a comparison with macroscopic results obtained previously from Rutherford backscattering spectrometry (RBS) measurements will be presented to confirm our EELS quantification at the nanoscale.…”

“…[19][20][21][22][23][24][25] Generally these microstructures consist in few pores situated at a certain distance from the surface; while with our methodology, highly porous structures with uniform porosity from the substrate to the coatings surface are deposited, in a wide range of thicknesses (from 100 nm to few microns). From a fundamental point of view these new materials with embedded pores, filled with the sputtering gas, represent a new class of nanocomposite materials presenting on demand optical properties in comparison with the matrix film.…”

Enhanced Solar Water Splitting Performance of 50-100 nm Pore Sized TiO2 Nanotubes

“…Later, benefiting from annealing effect, the intensity of the diffraction peaks analogous to the anatase and rutile phases are getting increased. This was accredited to the annealing effect [39], besides, annealing is renowned to improve the crystalline nature of the material [40]. Figs.…”

Formation of TiO2 nanorods by ion irradiation

“…12 Recently, Romero-Gomez et al obtained various surface nanostructures on anatase TiO 2 thin films, such as cellular defect structures or nanorod surface patterns aligned with the angle of incidence of the beam by ion irradiation. 13 However, the formation mechanism of the surface nanostructures induced by ion irradiation is still a controversial issue. For GaN thin films irradiated by Au þ ions, 14,15 a stoichiometric imbalance of N and Ga in the network induced the formation of multiple N 2 molecules, the aggregation and diffusion of which are responsible for the nanopore formation.…”