8 research outputs found
Ion induced segregation in gold nanostructured thin films on silicon
We report a direct observation of segregation of gold atoms to the near
surface regime due to 1.5 MeV Au2+ ion impact on isolated gold nanostructures
deposited on silicon. Irradiation at fluences of 6x10^13, 1x10^14 and 5x10^14
ions cm-2 at a high beam flux of 6.3x1012 ions cm-2 s-1 show a maximum
transported distance of gold atoms into the silicon substrate to be 60, 45 and
23 nm, respectively. At a lower fluence (6x1013 ions cm-2) transport has been
found to be associated with the formation of gold silicide (Au5Si2). At a high
fluence value of 5x10^14 ions cm-2, disassociation of gold silicide and
out-diffusion lead to segregation of gold to defect - rich surface and
interface region.Comment: 10 pages, 2 figure
Growth of silver nanoclusters embedded in soda glass matrix
Temperature-controlled-growth of silver nanoclusters in soda glass matrix is
investigated by low-frequency Raman scattering spectroscopy. Growth of the
nanoclusters is ascribed to the diffusion-controlled precipitation of silver
atoms due to annealing the silver-exchanged soda glass samples. For the first
time, Rutherford backscattering measurements performed in this system to find
out activation energy for the diffusion of silver ions in the glass matrix.
Activation energy for the diffusion of silver ions in the glass matrix
estimated from different experimental results is found to be consistent.Comment: 16 pages, 5 figures, pdf fil
X-ray standing wave and reflectometric characterization of multilayer structures
Microstructural characterization of synthetic periodic multilayers by x-ray
standing waves have been presented. It has been shown that the analysis of
multilayers by combined x-ray reflectometry (XRR) and x-ray standing wave (XSW)
techniques can overcome the deficiencies of the individual techniques in
microstructural analysis. While interface roughnesses are more accurately
determined by the XRR technique, layer composition is more accurately
determined by the XSW technique where an element is directly identified by its
characteristic emission. These aspects have been explained with an example of a
20 period Pt/C multilayer. The composition of the C-layers due to Pt
dissolution in the C-layers, PtC, has been determined by the XSW
technique. In the XSW analysis when the whole amount of Pt present in the
C-layers is assumed to be within the broadened interface, it l eads to larger
interface roughness values, inconsistent with those determined by the XRR
technique. Constraining the interface roughness values to those determined by
the XRR technique, requires an additional amount of dissolved Pt in the
C-layers to expl ain the Pt fluorescence yield excited by the standing wave
field. This analysis provides the average composition PtC of the
C-layers .Comment: 12 pages RevTex, 10 eps figures embedde