Disorder in Au and Cu nanocrystals formed by ion implantation into thin SiO2

Au and Cu nanocrystals (NCs) fabricated by ion implantation into thin SiO2 and annealing were investigated by means of extended X-ray absorption fine structure (EXAFS) spectroscopy and transmission electron microscopy (TEM). In particular, the EXAFS Debye-Waller (D-W) factor is studied as a function of the annealing temperature. An increased D-W factor was observed for annealing temperatures 500 °C and 800 °C with respect to samples as implanted and annealed at 1100 °C. A possible explanation for this behavior could be stress induced plastic deformation due to the different thermal expansion of the metals and the SiO2.