Shallow nanoporous surface layers produced by helium ion implantation

High-dose helium implantation of metals can result in the formation of nano porous bubble structures with striking features. These structures which may be a universal response for all metals implanted under appropriate conditi ons, show considerable promise for applications such as catalysis. They are characterized by nanoscale cavities of uniform size, a high degree of swel ling and extremely thin metal walls (similar to1 nm in thickness) separatin g nearest neighbor cavities The internal surface area associated with the c avities is high and the method of production offers the potential for contr olling pore size through the selection of implant parameters.