Dowd, ALlewellyn, DavidElliman, RobertLuther-Davies, BarrySamoc, MarekFitz Gerald, John2015-12-100168-583Xhttp://hdl.handle.net/1885/69801Ge nanocrystals formed in silica by implantation with 1.0 MeV Ge ions and subsequent annealing at 1100°C were characterised by transmission electron microscopy and Raman spectroscopy. The nanocrystals were found to be approximately spherical in shape andKeywords: Annealing; Crystal structure; Four wave mixing; Ion implantation; Nanostructured materials; Nonlinear optics; Raman spectroscopy; Refractive index; Relaxation processes; Semiconducting germanium; Silica; Transmission electron microscopy; Degenerative four Four-wave mixing; Ion-implantation; Nanocrystals; Nonlinear optics; z-scan200110.1016/S0168-583X(00)00536-X2015-12-10