Density and pressure of helium in small bubbles in metals

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).…”

A description of bubble growth and gas release of helium implanted tungsten

“…The equilibrium condition however requires that the newly formed bubble instantaneously grows in size to accommodate the internal pressure. However, helium gas pressures indicating solid state conditions have been measured for matrix bubbles in nickel and aluminum [16]. At elevated pressures, plastic deformation of the material surrounding the bubble can occurs, which would result in slowing down or even self-pinning of the bubble.…”

A description of stress driven bubble growth of helium implanted tungsten

“…The equilibrium condition requires that the newly formed bubble instantaneously grows in size to accommodate the high internal pressure. For small bubbles, inside the matrix helium gas pressures indicating solid state conditions have been measured for matrix bubbles in nickel and aluminum [37]. Furthermore, at elevated pressures, plastic deformation of the material surrounding the bubble can occur, which would result in slowing down or even self-pinning of the bubble.…”