A TEM investigation of solid krypton bubbles formed in cobalt by ion implantation

Transmission electron microscopy has been used to study the effect of ion implantation of krypton ions into cobalt. This has been found to result in the formation of a high concentration of bubbles, with those having diameters below ≈3 nm being solid at room temperature. Electron diffraction has been used to characterise these solid bubbles, or precipitates, and this has shown them to possess a hcp crystalline structure, and to exhibit an epitaxial relationship with the matrix. Bubble ordering into rafts parallel to the basal plane of the metal has also been observed, although the bubble positionwithin the rafts appeared random. These results extend the data available on inert gas precipitation in hcp metals.