Aggregation and out diffusion of iron atoms for Fe ion implanted silica films

Abstract

Low temperature oxidation of SiC preamorphized by ion implantation J. Appl. Phys. 95, 6119 (2004); 10.1063/1.1703822 Diamond nanocrystals formed by direct implantation of fused silica with carbon

Diffusion of germanium in silica glass

“…For example, it has been reported that the concentration peak of implanted ions of gallium [16], bismuth [17], arsenic [18,19], and iron [20,21] shifts toward the surface during annealing. This effect has been referred to as Ôout diffusionÕ.…”

Catalytic chemical vapor deposition of vertically aligned carbon nanotubes on iron nanoislands formed from Fe+-implanted SiO2 films

“…An iron ion beam at an accelerating voltage of 62 kV was implanted into the silica film up to a dose of 6.5 · 10 16 Fe/cm 2 by using a metal vapor vacuum arc (MEVVA) ion implantor. The maximum iron atom concentration is about 6.5 · 10 21 at/cm 3 , or about 9 at.% in the silica film, as calculated by the TRIM simulation and measured by the Rutherford backscattering spectroscopy analysis as well [8]. Then the as-implanted film was annealed at 800°C in a flowing nitrogen atmosphere (N 2 flow rate: $5 l/min) for 0.5 and 2 h, respectively.…”

“…1 shows the AFM images of the samples annealed at 800°C for 0.5 h (left) and 2 h (right), respectively. It can be seen that a lot of nanometer scale islands, which have been confirmed to be iron particles with a thin oxide shell [8], appeared on the sample surface. The size and area density of these islands depend on the annealing conditions.…”

“…In our previous paper [8], iron ions were implanted into a thermally grown silica film. After appropriate annealing processes, the implanted iron atoms would diffuse out of the film and aggregated by forming nanometer-sized iron islands on the film surface.…”

Carbon nanotube growth from ion-implanted catalyst by chemical vapor deposition

“…(4) Ion implantation is easily scalable to larger substrates. (5) Use of an insulating thin film, such as oxide, as a host for nanocrystalline particles has been shown to be an effective method for tailoring a uniform particle size, and controlling the homogeneous dispersion of nanoclusters [13]. These properties make ion implanted transition metals very attractive candidates as nanotube catalysts, since more uniform size results in more uniform nanotube diameter, and homogenous dispersion results in higher growth yield.…”