Surface Diffusion and Island Growth

2007 ◽  
Vol 263 ◽  
pp. 177-182 ◽  
Author(s):  
Rüdiger Reitinger ◽  
B. Pfau ◽  
L.M. Stadler ◽  
S. Stankov ◽  
M. Zajac ◽  
...  

Grazing-Incidence Small Angle X-ray Scattering (GISAXS) and X-Ray Photon Correlation Spectroscopy (XPCS) studies of island growth in two different systems are presented: 5 ML of iron on MgO(001) and 10 ML of iron on Au(001). Due to a missing conducting surface Fe/MgO thinner than approximately 20 ML could not be studied previously by common methods like STM. Fe/Au(001) is interesting as atoms of gold diffuse easily through iron layers and form precipitates. The coarsening dynamics of these precipitates is investigated by XPCS in GISAXS geometry. Their growth depends on the crystallographic directions of the substrate and correlates with the morphology measured by STM microscopy. Measurements were performed at the ESRF in Grenoble.

2011 ◽  
Vol 44 (1) ◽  
pp. 200-212 ◽  
Author(s):  
F. Zhang ◽  
A. J. Allen ◽  
L. E. Levine ◽  
J. Ilavsky ◽  
G. G. Long ◽  
...  

This paper describes the development of ultra-small-angle X-ray scattering–X-ray photon correlation spectroscopy (USAXS–XPCS). This technique takes advantage of Bonse–Hart crystal optics and is capable of probing the long-time-scale equilibrium and non-equilibrium dynamics of optically opaque materials with prominent features in a scattering vector range between those of dynamic light scattering and conventional XPCS. Instrumental parameters for optimal coherent-scattering operation are described. Two examples are offered to illustrate the applicability and capability of USAXS–XPCS. The first example concerns the equilibrium dynamics of colloidal dispersions of polystyrene microspheres in glycerol at 10, 15 and 20% volume concentrations. The temporal intensity autocorrelation analysis shows that the relaxation time of the microspheres decays monotonically as the scattering vector increases. The second example concerns the non-equilibrium dynamics of a polymer nanocomposite, for which it is demonstrated that USAXS–XPCS can reveal incipient dynamical changes not observable by other techniques.


2020 ◽  
Vol 53 (19) ◽  
pp. 8233-8243
Author(s):  
Ronald M. Lewis ◽  
Grayson L. Jackson ◽  
Michael J. Maher ◽  
Kyungtae Kim ◽  
Suresh Narayanan ◽  
...  

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