Strain and Shape in Self-Assembled Quantum Dots Studied by X-Ray Grazing Incidence Diffraction

1998 ◽  
Vol 524 ◽  
Author(s):  
I. Kegel ◽  
T. H. Metzger ◽  
J. Peisl ◽  
P. Fratzl ◽  
A. Lorke ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Reciprocal Space Mapping ◽  
X Ray ◽  
Surface Reflection ◽  
Grazing Incidence Diffraction ◽  
Shape Effects ◽  
Outer Perimeter ◽  
Highly Strained

ABSTRACTWe have developed a method to determine the relationship between strain and lateral size of coherent self-organized quantum dots. In our approach, X-ray grazing incidence diffraction is used to collect information on strain and shape effects in the vicinity of a prominent surface reflection. We demonstrate that for highly strained nano-scale islands it is possible to separate strain-induced and form factor-induced scattering without comparing different reflections. Experimental data from InAs on GaAs(100) quantum dots is discussed with respect to this model. Reciprocal space mapping around the (220) surface reflection shows a linear relationship between relaxation from the substrate lattice parameter and the outer perimeter of the dot. In addition, the functional form of the gradient of relaxation is found to be nonmonotonous and rapidly increasing towards the tip of the dot.

Vertical alignment of multilayered quantum dots studied by x-ray grazing-incidence diffraction

1999 ◽  
Vol 60 (4) ◽  
pp. 2516-2521 ◽  
Author(s):  
I. Kegel ◽  
T. H. Metzger ◽  
J. Peisl ◽  
J. Stangl ◽  
G. Bauer ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Grazing Incidence ◽  
Vertical Alignment ◽  
X Ray ◽  
Grazing Incidence Diffraction

scholarly journals Grazing-incidence X-ray diffraction of single GaAs nanowires at locations defined by focused ion beams

2013 ◽  
Vol 46 (4) ◽  
pp. 887-892 ◽  
Author(s):  
Genziana Bussone ◽  
Rüdiger Schott ◽  
Andreas Biermanns ◽  
Anton Davydok ◽  
Dirk Reuter ◽  
...  
Keyword(s):  
Gaas Substrate ◽  
Lattice Spacing ◽  
Molecular Beam ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Ion Beams ◽  
Focused Ion Beams ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gaas Nanowires

Grazing-incidence X-ray diffraction measurements on single GaAs nanowires (NWs) grown on a (111)-oriented GaAs substrate by molecular beam epitaxy are reported. The positions of the NWs are intentionally determined by a direct implantation of Au with focused ion beams. This controlled arrangement in combination with a nanofocused X-ray beam allows the in-plane lattice parameter of single NWs to be probed, which is not possible for randomly grown NWs. Reciprocal space maps were collected at different heights along the NW to investigate the crystal structure. Simultaneously, substrate areas with different distances from the Au-implantation spots below the NWs were probed. Around the NWs, the data revealed a 0.4% decrease in the lattice spacing in the substrate compared with the expected unstrained value. This suggests the presence of a compressed region due to Au implantation.

scholarly journals Synthesis of CdS nanocrystals in polymeric films studied by in-situ GID and GISAXS

2015 ◽  
Vol 1810 ◽  
Author(s):  
Tiziana Di Luccio ◽  
Dina Carbone ◽  
Silvia Masala ◽  
Karthik Ramachandran ◽  
Julie Kornfield
Keyword(s):  
Hexagonal Lattice ◽  
Grazing Incidence ◽  
Lattice Parameter ◽  
Polymeric Films ◽  
Diffraction Intensity ◽  
Cds Nanocrystals ◽  
Grazing Incidence Diffraction ◽  
Angle Scattering ◽  
Precursor Structure

ABSTRACTIn this work, we describe the synthesis of CdS nanocrystals in thin polymeric films by in-situ Grazing Incidence Diffraction (GID) and Grazing Incidence Small Angle Scattering (GISAXS). The 2D GISAXS patterns indicate how the precursor structure is altered as the temperature is varied from 25°C to 300°C. At 150°C, the CdS nanocrystals start to arrange themselves in a hexagonal lattice with a lattice parameter of 27 Å. The diffraction intensity from the hexagonal lattice reaches a maximum at 170°C and decreases steadily upon further heating above 220°C indicating loss of symmetry. Correspondingly, the GID scans at 170°C show strong crystalline peaks from cubic CdS nanocrystals that are about 2 nm size. The results indicate that a temperature of 170°C is sufficient to synthesize CdS nanocrystals without degradation of the polymer matrix (Topas) in thin films (about 30nm).

Erratum: X‐ray grazing incidence diffraction from alkylsiloxane monolayers on silicon wafers [J. Chem. Phys. 95, 2854 (1991)]

1993 ◽  
Vol 98 (2) ◽  
pp. 1754-1754
Author(s):  
I. M. Tidswell ◽  
T. A. Rabedeau ◽  
P. S. Pershan ◽  
S. D. Kosowsky ◽  
J. P. Folkers ◽  
...  
Keyword(s):  
Grazing Incidence ◽  
Chem Phys ◽  
Silicon Wafers ◽  
X Ray ◽  
Grazing Incidence Diffraction

Grazing incidence diffraction of cadmium arachidate multilayers at the solid-liquid interface

2005 ◽  
Vol 220 (12) ◽  
Author(s):  
Chad E. Miller ◽  
Jaroslaw Majewski ◽  
Thomas Gog ◽  
Tonya L. Kuhl
Keyword(s):  
Arachidic Acid ◽  
Grazing Incidence ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Layers ◽  
Grazing Incidence Diffraction ◽  
Synchrotron Beam ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Monochromatic Synchrotron

AbstractUsing complementary X-ray reflectivity (XR) and grazing incidence X-ray diffraction (GIXD), we report structural studies of supported thin-organic layers in contact with water and air. Using a monochromatic synchrotron beam to penetrate 10 mm of liquid, we have characterized buried films composed of 12.5 repeating bilayers of arachidic acid (C

Waveguide-enhanced scattering from thin biomolecular films

2002 ◽  
Vol 35 (2) ◽  
pp. 163-167 ◽  
Author(s):  
F. Pfeiffer ◽  
U. Mennicke ◽  
T. Salditt
Keyword(s):  
Lipid Bilayers ◽  
Signal To Noise Ratio ◽  
Acyl Chain ◽  
Grazing Incidence ◽  
Waveguide Structure ◽  
X Ray Diffraction ◽  
Signal To Noise ◽  
X Ray ◽  
Grazing Incidence Diffraction ◽  
Chain Ordering

An X-ray diffraction experiment on multilamellar membranes incorporated into an X-ray waveguide structure is reported. In the device, the lipid bilayers are confined to one side by the silicon substrate and to the other side by an evaporated thin metal cap layer. Shining a highly brilliant X-ray beam onto the system, resonantly enhanced, precisely defined and clearly distinguishable standing-wavefield distributions (modes) are excited. The in-plane structure of the acyl chain ordering is then studied by grazing incidence diffraction under simultaneously excited modes. A significant gain in signal-to-noise ratio as well as enhanced spatial resolution can be obtained with such a setup.

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