Report on a round-robin study of diffuse X-ray scattering

1986 ◽  
Vol 19 (3) ◽  
pp. 188-194 ◽  
Author(s):  
K. Ohshima ◽  
J. Harada ◽  
M. Morinaga ◽  
P. Georgopoulos ◽  
J. B. Cohen
Keyword(s):  
High Resolution ◽  
High Intensity ◽  
Diffuse Scattering ◽  
Reciprocal Space ◽  
X Ray ◽  
Absolute Intensities ◽  
X Ray Scattering ◽  
Insertion Device ◽  
The Us ◽  
Sample Chamber

The diffuse scattering in a volume in reciprocal space from NbC0.72 was measured on an absolute scale at two synchrotron sources (in the US and in Japan) and with a high-intensity rotating-anode source (in Japan). The shape and actual absolute intensities agreed to a few percent. Special problems associated with such measurements at a synchrotron are noted, especially with an insertion device. The high resolution possible at such sources reduces the need for an evacuated sample chamber. Detailed measurements can be completed in 1–2 d, making such studies much more accessible than is possible with sealed-tube X-ray generation.

scholarly journals High-resolution SAXS setup with tuneable resolution in direct and reciprocal space: a new tool to study ordered nanostructures

2019 ◽  
Vol 52 (5) ◽  
pp. 1095-1103
Author(s):  
Andrei P. Chumakov ◽  
Kirill S. Napolskii ◽  
Andrei V. Petukhov ◽  
Anatoly A. Snigirev ◽  
Irina I. Snigireva ◽  
...  
Keyword(s):  
High Resolution ◽  
Hexagonal Structure ◽  
Reciprocal Space ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Detector Position ◽  
Alumina Membranes ◽  
X Ray Scattering ◽  
Ordered Nanostructures ◽  
Aluminium Oxide Film

A novel compact small-angle X-ray scattering (SAXS) setup with tuneable resolution in both direct and reciprocal space has been designed and tested for the study of nanostructured materials with a hierarchical structure. The setup exploits a set of compound refractive lenses that focus the X-ray beam at the detector position. Anodic alumina membranes with a self-ordered porous structure were chosen as test samples. The setup allows patterns to be collected with a minimum scattering vector value of 0.001 nm−1 and gives the possibility for an easy continuous switch between taking high-resolution statistically averaged diffraction data of macroscopically large sample volumes and lower-resolution diffraction on a small single domain of the anodic aluminium oxide film. It is revealed that the pores are longitudinal and their ordering within each domain tends towards the ideal hexagonal structure, whereas the in-plane orientation of the pore arrays changes from domain to domain. The possible advantages and disadvantages of the proposed compact SAXS scheme are discussed.

Study of Diffuse Scattering by Means of High Resolution Structure Images

1976 ◽  
Vol 34 ◽  
pp. 476-477
Author(s):  
Sumio Iijima ◽  
G. R. Anstis
Keyword(s):  
High Resolution ◽  
Neutron Diffraction ◽  
Diffuse Scattering ◽  
Reciprocal Space ◽  
The Other ◽  
X Ray ◽  
Actual Model ◽  
High Resolution Structure ◽  
Made In ◽  
Resolution Structure

Disorders in crystals with relatively simple structures which gave diffuse scattering have been extensively studied by X-ray or neutron diffraction methods. All these investigations were based on traditional diffraction methods and observations were made in reciprocal space (note observable diffraction intensities can be considered only in terms of interatomic vectors) and therefore the results obtained there leaves considerable ambiguity, particularly when we try to derive an actual model of the disordered crystals. A solution of this problem will be given only by knowing all atom positions in an assembly of atoms and for this case the observable diffracted intensity is given bywhere (xi,yi) and (xj,yj) represent position vectors of the i th and j th atoms with scattering factors fi and fj from an arbitrary origin. On the other hand, a crystal containing imperfections can be defined by

High-energy X-ray diffuse scattering using Weissenberg flat-cone geometry

2000 ◽  
Vol 33 (4) ◽  
pp. 1046-1050 ◽  
Author(s):  
B. D. Butler ◽  
D. R. Haeffner ◽  
P. L. Lee ◽  
T. R. Welberry
Keyword(s):  
Diffuse Scattering ◽  
High Energy ◽  
Reciprocal Space ◽  
Irregular Shape ◽  
X Rays ◽  
Storage Phosphor ◽  
X Ray ◽  
Image Plate ◽  
X Ray Scattering ◽  
Disordered Crystal

A technique for the measurement of diffuse X-ray scattering on individual reciprocal-space planes using high-energy X-ray photons is described. The method is demonstrated using a disordered crystal of the compound TlSbOGeO4and compared to data collected with a sealed-tube Cu anode source. Measurements were made on a synchrotron undulator beamline at an energy of 45 keV using Weissenberg flat-cone geometry and a storage phosphor (image) plate to detect the scattered X-rays. Advantages of the method include: extension of the accessible diffraction space to both higherandlower wavevectors, the ability to use crystals of irregular shape without the need for complicated absorption corrections, less need to prepare sample surfaces carefully, and the ability to filter fluorescence simply.

scholarly journals Aperiodic atomic ordering in PMN recovered from the anomalous x-ray scattering

2014 ◽  
Vol 70 (a1) ◽  
pp. C1758-C1758
Author(s):  
Miloš Kopecký ◽  
Jiří Kub ◽  
Jan Fábry ◽  
Zbyněk Šourek
Keyword(s):  
Absorption Edge ◽  
Diffuse Scattering ◽  
Imaging Techniques ◽  
Relaxor Ferroelectrics ◽  
Reciprocal Space ◽  
Anomalous Scattering ◽  
Space Images ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

Various imaging techniques with atomic resolutions have been developed to study 3D arrangement of atoms in sub-nanometer and nanometer scale. The method presented is based on the measurement of the anomalous portion of x-ray scattering in large volume of the reciprocal space. It can be shown that, by analogy to x-ray holography with atomic resolution, the anomalous diffuse scattering provides information on both the amplitude and the phase of the scattered wave. The sample was PbMg1/3Nb2/3O3 (PMN), which belongs to relaxor ferroelectrics. Although the short and intermediate range chemical ordering is responsible for its relaxor behaviour, the real arrangement of cations remains unclear so far. The intensities of x-ray scattering in a large 3D volume of the reciprocal space were measured using an intense x-ray radiation generated by the synchrotron facility. Anomalous x-ray scattering has been obtained as a difference of intensity maps collected at two energies. The energy E1 just below the Nb K absorption edge was chosen in order to get a strong anomalous component in the scattering from Nb atoms. The data acquired at the energy E2 far from the absorption edge were used as the reference. The measured 3D pattern of anomalous scattering, including both discrete diffraction peaks and continuous x-ray diffuse scattering, allows us to reconstruct numerically an average environment around Nb atoms. The reconstructed real-space images clearly show a systematic local ordering of Mg2+ and Nb5+ cations. This ordering is more significant close to the central reference Nb atom but it is still apparent at the distance of about 3 nm giving thus an idea on the average size of ordered regions. More distant sites are occupied randomly with probabilities of occurrence of Mg2+ and Nb5+ cations given by their relative fraction in the sample. It is possible to determine conditioned probabilities of site occupancies by the given type of atom provided that the central site is occupied by Nb and to get information on the structure model of the ordered regions in the crystal.

Diffuse X-ray scattering from local chemical inhomogeneities in InGaN layers

2018 ◽  
Vol 51 (4) ◽  
pp. 969-981 ◽  
Author(s):  
Václav Holý ◽  
Marcin Kryśko ◽  
Michał Leszczyński
Keyword(s):  
Diffuse Scattering ◽  
Reciprocal Space ◽  
Space Distribution ◽  
Misfit Dislocations ◽  
X Ray Diffraction ◽  
Linear Elasticity Theory ◽  
X Ray ◽  
X Ray Scattering ◽  
Simulation Results ◽  
Ray Scattering

Diffuse X-ray scattering from random chemical inhomogeneities in epitaxial layers of InGaN/GaN was simulated using linear elasticity theory and kinematical X-ray diffraction. The simulation results show the possibility of determining the r.m.s. deviations of the local In content and its lateral correlation length from reciprocal-space maps of the scattered intensity. The reciprocal-space distribution of the intensity scattered from inhomogeneities is typical and it can be distinguished from other sources of diffuse scattering such as threading or misfit dislocations.

Evolution of Interfacial Roughness Correlations of Fe Au Films Grown on Mgo(001) Substrates

1996 ◽  
Vol 440 ◽  
Author(s):  
P. C. Chow ◽  
R. Paniago ◽  
R. Forrest ◽  
S. C. Moss ◽  
S. S. P. Parkin ◽  
...  
Keyword(s):  
Thin Films ◽  
Diffuse Scattering ◽  
Perfect Match ◽  
Grazing Incidence ◽  
Interface Roughness ◽  
Metallic Structures ◽  
X Ray ◽  
Dimensional Image ◽  
X Ray Scattering ◽  
Image Plate Detector

AbstractThe growth by sputtering of a series of thin films of Fe/Au on MgO(001) substrates was analyzed using Bragg and diffuse X-ray scattering. The Fe (bcc) layer grows rotated by 45° with respect to the MgO – Au(fcc) (001) epitaxial orientation, resulting in an almost perfect match between the two metallic structures. By collecting the X-ray diffuse scattering under grazing incidence using a 2-dimensional image plate detector, we mapped the reciprocal space of these films. We characterized the correlated interface roughness starting with a buffer of Fe in which only three interfaces are present. The propagation of the roughness was subsequently characterized for Fe/Au multilayers with 40 and 100 bilayers. We observe an enlargement of the surface features as a function of time, evidenced by the longer lateral cutoff length measured for thicker films.

A high-throughput assembly of beam-shaping channel-cut monochromators for laboratory high-resolution X-ray diffraction and small-angle X-ray scattering experiments

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Peter Nadazdy ◽  
Jakub Hagara ◽  
Petr Mikulik ◽  
Zdenko Zaprazny ◽  
Dusan Korytar ◽  
...  
Keyword(s):  
High Resolution ◽  
Small Angle ◽  
Photon Flux ◽  
Photon Flux Density ◽  
X Ray Diffraction ◽  
High Beam ◽  
X Ray ◽  
X Ray Scattering ◽  
Beam Collimation ◽  
Ray Scattering

A four-bounce monochromator assembly composed of Ge(111) and Ge(220) monolithic channel-cut monochromators with V-shaped channels in a quasi-dispersive configuration is presented. The assembly provides an optimal design in terms of the highest transmittance and photon flux density per detector pixel while maintaining high beam collimation. A monochromator assembly optimized for the highest recorded intensity per detector pixel of a linear detector placed 2.5 m behind the assembly was realized and tested by high-resolution X-ray diffraction and small-angle X-ray scattering measurements using a microfocus X-ray source. Conventional symmetric and asymmetric Ge(220) Bartels monochromators were similarly tested and the results were compared. The new assembly provides a transmittance that is an order of magnitude higher and 2.5 times higher than those provided by the symmetric and asymmetric Bartels monochromators, respectively, while the output beam divergence is twice that of the asymmetric Bartels monochromator. These results demonstrate the advantage of the proposed monochromator assembly in cases where the resolution can be partially sacrificed in favour of higher transmittance while still maintaining high beam collimation. Weakly scattering samples such as nanostructures are an example. A general advantage of the new monochromator is a significant reduction in the exposure time required to collect usable experimental data. A comparison of the theoretical and experimental results also reveals the current limitations of the technology of polishing hard-to-reach surfaces in X-ray crystal optics.

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