A procedure for measuring the helium density and pressure in nanometre-sized bubbles in irradiated materials using electron-energy-loss spectroscopy

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).…”

“…This is a usual way to limit surface effects (see for example Ref. reported in helium bubbles 18,[26][27] can be attributed to the equilibrium condition of the surface energy of the matrix with the internal N 2 pressure of the pore. This point is actually under investigation in our laboratory for a future study.…”

“…of nanobubbles or nanopores filled with helium for which quantification has already been achieved in various studies, 15,18,[26][27][28][29] only a few works attempted to evaluate the N 2 density and pressure inside closed cavities. [30][31][32] Most of them were done in a semi-quantitative way based on the variation of the N-K edge intensity over the nitride matrix and over the pore.…”

“…33 To our knowledge, only one work of the literature 32 has reported the quantification of nitrogen density from EELS based on Ref. 18, but very few details of the analysis were given (in particular the way to record and process the EELS data to get the zero-loss and N-K edge intensities). In addition, this study was performed on an ideal case with a surrounding matrix free of nitrogen.…”

Structure and photoionization of confined atoms

“…o and Mih! aly, 2001), the chemical reactivity and chemical valence of atoms (Lawrence et al, 1981), the reversible storage of ions in certain solids (Connerade, 1997;Connerade and Semaoune, 2000a), the appearance of helium bubbles under high pressure in the walls of nuclear reactors (Walsh et al, 2000), and ESR, NMR and magnetic moments of compressed atoms (Buchachenko, 2001), etc. Confined atoms are also very close in principle to the concepts underpinning confinement within ''quantum dots'' (Johnson, 1995;Sako and Diercksen, 2003a, b).…”