An insight into real and average structure from diffuse X-ray scattering – a case study

2016 ◽  
Vol 72 (4) ◽  
pp. 571-583 ◽  
Author(s):  
Michał Leszek Chodkiewicz ◽  
Anna Makal ◽  
Roman Gajda ◽  
Dragoslav Vidovic ◽  
Krzysztof Woźniak
Keyword(s):  
Diffuse Scattering ◽  
Organic Salt ◽  
X Ray ◽  
Average Structure ◽  
X Ray Scattering ◽  
The Difference ◽  
The Relationship ◽  
Insight Into ◽  
Ray Scattering

Two-dimensional diffuse X-ray scattering from an organic salt [N-(3-(2,6-dimethylanilino)-1-methylbut-2-enylidene)-2,6-dimethylanilinium chloride, C21H27N2+Cl−] was interpreted with the help of an analytical model of diffuse scattering. An analysis of the relationship between symmetry and diffuse scattering for the studied system has been undertaken. The symmetry of the system explains the extinction pattern, taking the form of curves, on the diffuse scattering planes. We have also tested the relationship between the average structure model and scattering intensities. Two models, differing in their representation of overlapping atoms, were used. In the case of diffuse scattering the difference between resulting intensities is immense, while for the Bragg intensities it is much smaller. This sensitivity of diffuse scattering could potentially be used to improve the description of the average structure.

scholarly journals Topology and temperature dependence of the diffuse X-ray scattering in Na0.5Bi0.5TiO3ferroelectric single crystals

2015 ◽  
Vol 48 (5) ◽  
pp. 1543-1550 ◽  
Author(s):  
Semën Gorfman ◽  
Dean S. Keeble ◽  
Alessandro Bombardi ◽  
Pam A. Thomas
Keyword(s):  
Temperature Dependence ◽  
Diffuse Scattering ◽  
Structural Changes ◽  
Structural Disorder ◽  
X Ray ◽  
Average Structure ◽  
X Ray Scattering ◽  
Starting Point ◽  
Lower Temperature ◽  
Ray Scattering

The results of high-resolution measurements of the diffuse X-ray scattering produced by a perovskite-based Na0.5Bi0.5TiO3ferroelectric single crystal between 40 and 620 K are reported. The study was designed as an attempt to resolve numerous controversies regarding the average structure of Na0.5Bi0.5TiO3, such as the mechanism of the phase transitions between the tetragonal,P4bm, and rhombohedral | monoclinic,R3c | Cc, space groups and the correlation between structural changes and macroscopic physical properties. The starting point was to search for any transformations of structural disorder in the temperature range of thermal depoling (420–480 K), where the average structure is known to remain unchanged. The intensity distribution around the {032} pseudocubic reflection was collected using a PILATUS 100K detector at the I16 beamline of the Diamond Light Source (UK). The data revealed previously unknown features of the diffuse scattering, including a system of dual asymmetric L-shaped diffuse scattering streaks. The topology, temperature dependence, and relationship between Bragg and diffuse intensities suggest the presence of complex microstructure in the low-temperatureR3c | Ccphase. This microstructure may be formed by the persistence of the higher-temperatureP4bmphase, built into a lower-temperatureR3c | Ccmatrix, accompanied by the related long-range strain fields. Finally, it is shown that a correlation between the temperature dependence of the X-ray scattering features and the temperature regime of thermal depoling is present.

Diffuse X-ray scattering from tiny sample volumes

2005 ◽  
Vol 220 (12) ◽  
Author(s):  
Gene E. Ice ◽  
Rozaliya I. Barabash ◽  
Wenjun Liu
Keyword(s):  
Local Structure ◽  
Diffuse Scattering ◽  
High Performance ◽  
Sensitive Area ◽  
X Ray ◽  
X Ray Scattering ◽  
Defect Content ◽  
Ray Scattering

AbstractThe emergence of intense synchrotron X-ray sources, efficient focusing optics and high-performance X-ray sensitive area detectors allows for measurements of diffuse scattering from cubic micron-scale sample vol umes. Here we present an experiment that illustrates methods for studying the local structure and defect content of tiny sample volumes. In the experiment, an X-ray microbeam illuminating about ∼5 μm

Diffuse x-ray scattering from InGaAs/GaAs quantum dots

2003 ◽  
Vol 799 ◽  
Author(s):  
Rolf Köhler ◽  
Daniil Grigoriev ◽  
Michael Hanke ◽  
Martin Schmidbauer ◽  
Peter Schäfer ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Synchrotron Radiation ◽  
Diffuse Scattering ◽  
Data Evaluation ◽  
X Ray ◽  
X Ray Scattering ◽  
Gaas Matrix ◽  
Wetting Layers ◽  
Ray Scattering

ABSTRACTMulti-fold stacks of In0.6Ga0.4As quantum dots embedded into a GaAs matrix were investigated by means of x-ray diffuse scattering. The measurements were done with synchrotron radiation using different diffraction geometries. Data evaluation was based on comparison with simulated distributions of x-ray diffuse scattering. For the samples under consideration ((001) surface) there is no difference in dot extension along [110] and [-110] and no directional ordering. The measurements easily allow the determination of the average indium amount in the wetting layers. Data evaluation by simulation of x-ray diffuse scattering gives an increase of Incontent from the dot bottom to the dot top.

A High-Energy Monochromatic Laue (MonoLaue) X-ray Diffuse Scattering Study of KMnF3 using an Image Plate

1997 ◽  
Vol 30 (1) ◽  
pp. 16-20 ◽  
Author(s):  
A. Gibaud ◽  
D. Harlow ◽  
J. B. Hastings ◽  
J. P. Hill ◽  
D. Chapman
Keyword(s):  
Diffuse Scattering ◽  
High Energy ◽  
Experimental Conditions ◽  
X Ray ◽  
Image Plate ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Diffraction Patterns ◽  
Ray Scattering

The technique of high-energy monochromatic Laue X-ray scattering using image plates to record the diffraction patterns is presented. A tunable wiggler beamline is used as an X-ray source. It is shown that such experimental conditions present many advantages over conventional tube sources and photographic films. A study of diffuse scattering in the perovskite compound KMnF3 is presented to illustrate this in a qualitative way.

Fundamentals of Kinematical X-Ray Scattering Theory

2014 ◽  
pp. 1-14
Keyword(s):  
Scattering Theory ◽  
Profile Analysis ◽  
Reciprocal Lattice ◽  
Line Profile Analysis ◽  
X Ray ◽  
X Ray Scattering ◽  
Basic Concepts ◽  
Lattice Planes ◽  
The Relationship ◽  
Ray Scattering

The broadening of X-ray line profiles is usually described by the kinematical scattering theory. In this chapter, the basic concepts and equations of the kinematical X-ray scattering are presented in order to better understand the theory of line profile analysis. The correlation between the crystal structure and the diffracted intensity distribution is shown. The scattering angles of the diffracted peak maxima are given by the Ewald construction in the reciprocal space. The correspondence between the reciprocal lattice vectors and the lattice planes is also presented, and the relationship between the scattering angle and the lattice plane spacing is given by Bragg’s law.

Insight into Asphaltene Nanoaggregate Structure Inferred by Small Angle Neutron and X-ray Scattering

2011 ◽  
Vol 115 (21) ◽  
pp. 6827-6837 ◽  
Author(s):  
Joëlle Eyssautier ◽  
Pierre Levitz ◽  
Didier Espinat ◽  
Jacques Jestin ◽  
Jérémie Gummel ◽  
...  
Keyword(s):  
Small Angle ◽  
X Ray ◽  
X Ray Scattering ◽  
Insight Into ◽  
Ray Scattering

Annealing Effects of Schottky Contacts on the Characteristics of 4H-SiC Schottky Barrier Diodes

1999 ◽  
Vol 572 ◽  
Author(s):  
S. C. Kang ◽  
B. H. Kum ◽  
S. J. Do ◽  
J. H. Je ◽  
M. W. SHIN
Keyword(s):  
Schottky Barrier ◽  
Schottky Barrier Diodes ◽  
X Ray ◽  
Annealing Temperatures ◽  
X Ray Scattering ◽  
Different Temperatures ◽  
Annealing Effects ◽  
Evolution Of Microstructure ◽  
The Relationship ◽  
Ray Scattering

ABSTRACTThis paper reports on the relationship between the microstructure and the device performance of Pt/4H-SiC schottky barrier diodes ( SBDs ). The evolution of microstructure in the metal/SiC interfaces annealed at different temperatures was characterized using X-ray scattering techniques. The reverse characteristics of the devices were degraded with annealing temperatures. The maximum breakdown voltages of as-deposited devices and 850 °C annealed devices are 1300 V and 626 V, respectively. However, the forward characteristics of the devices were found out to improve with annealing temperatures. X-ray scattering analysis showed that Pt-silicides were formed by annealing performed at or higher than 650 °C. The formation of silicides was shown to increase the roughness of the Pt/SiC interface. It is believed that the forward characteristics of the SBDs be strongly dependent on the crystallity of silicides formed in the Pt/SiC interface during the annealing process.

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