scholarly journals Fluorination of Diamond Nanoparticles in Slow Neutron Reflectors Does Not Destroy Their Crystalline Cores and Clustering While Decreasing Neutron Losses

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3337
Author(s):  
Alexei Bosak ◽  
Artur Dideikin ◽  
Marc Dubois ◽  
Oleksandr Ivankov ◽  
Egor Lychagin ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Slow Neutron ◽  
Experimental Techniques ◽  
X Rays ◽  
Large Reduction ◽  
Diamond Nanoparticles ◽  
Angle Scattering ◽  
Scale Range ◽  
Technological Interest

If the wavelength of radiation and the size of inhomogeneities in the medium are approximately equal, the radiation might be intensively scattered in the medium and reflected from its surface. Such efficient nanomaterial reflectors are of great scientific and technological interest. In previous works, we demonstrated a significant improvement in the efficiency of reflection of slow neutrons from a powder of diamond nanoparticles by replacing hydrogen located on the surface of nanoparticles with fluorine and removing the residual sp2 amorphous shells of nanoparticles via the fluorination process. In this paper, we study the mechanism of this improvement using a set of complementary experimental techniques. To analyze the data on a small-angle scattering of neutrons and X-rays in powders of diamond nanoparticles, we have developed a model of discrete-size diamond nanospheres. Our results show that fluorination does not destroy either the crystalline cores of nanoparticles or their clustering in the scale range of 0.6–200 nm. This observation implies that it does not significantly affect the neutron scattering properties of the powder. We conclude that the overall increase in reflectivity from the fluorinated nanodiamond powder is primarily due to the large reduction of neutron losses in the powder caused by the removal of hydrogen contaminations.

Mesoscopic structure of SiC fibers by neutron and x-ray scattering

1996 ◽  
Vol 11 (5) ◽  
pp. 1169-1178 ◽  
Author(s):  
Kentaro Suzuya ◽  
Michihiro Furusaka ◽  
Noboru Watanabe ◽  
Makoto Osawa ◽  
Kiyohito Okamura ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Volume Fraction ◽  
X Rays ◽  
X Ray ◽  
Sic Fibers ◽  
X Ray Scattering ◽  
Mesoscopic Structure ◽  
Angle Scattering ◽  
Momentum Transfer Range ◽  
First Time

Mesoscopic structures of SiC fibers produced from polycarbosilane by different methods were studied by diffraction and small-angle scattering of neutrons and x-rays. Microvoids of a size of 4–10 Å in diameter have been observed for the first time by neutron scattering in a medium momentum transfer range (Q = 0.1–1.0 Å−1). The size and the volume fraction of β–SiC particles were determined for fibers prepared at different heat-treatment temperatures. The results show that wide-angle neutron scattering measurements are especially useful for the study of the mesoscopic structure of multicomponent materials.

Advanced Synchrotron Radiation and Neutron Scattering Techniques for Microstructural Characterization in Industrial Research

2017 ◽  
Vol 750 ◽  
pp. 53-66
Author(s):  
Fabrizio Fiori ◽  
Emmanuelle Girardin ◽  
Alessandra Giuliani ◽  
Adrian Manescu ◽  
Serena Mazzoni ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Spatial Resolution ◽  
Small Angle ◽  
3D Imaging ◽  
Volume Fraction ◽  
Rapid Development ◽  
Small Angle Scattering ◽  
Bragg Diffraction ◽  
X Rays ◽  
Angle Scattering

The rapid development of new materials and their application in an extremely wide variety of research and technological fields has lead to the request of increasingly sophisticated characterization methods. In particular residual stress measurements by neutron diffraction, small angle scattering of X-rays and neutrons, as well as 3D imaging techniques with spatial resolution at the micron or even sub-micron scale, like micro-and nano-computerized tomography, have gained a great relevance in recent years.Residual stresses are autobalancing stresses existing in a free body not submitted to any external surface force. Several manufacturing processes, as well as thermal and mechanical treatments, leave residual stresses within the components. Bragg diffraction of X-rays and neutrons can be used to determine residual elastic strains (and then residual stresses by knowing the material elastic constants) in a non-destructive way. Small Angle Scattering of neutrons or X-rays, complementary to Transmission Electron Microscopy, allows the determination of structural features such as volume fraction, specific surface and size distribution of inhomogeneities embedded in a matrix, in a huge variety of materials of industrial interest. X-ray microtomography is similar to conventional Computed Tomography employed in Medicine, allowing 3D imaging of the investigated samples, but with a much higher spatial resolution, down to the sub-micron scale. Some examples of applications of the experimental techniques mentioned above are described and discussed.

Small-Angle Scattering of Neutrons and X-Rays

2015 ◽  
pp. 1-11
Author(s):  
Naveed A Nadvi ◽  
John YH Chow ◽  
Jill Trewhella
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
X Rays ◽  
Angle Scattering

scholarly journals Small Angle Scattering of X-Rays

1968 ◽  
Vol 8 (2) ◽  
pp. 72-80
Author(s):  
Masao KAKUDO
Keyword(s):  
Small Angle ◽  
Small Angle Scattering ◽  
X Rays ◽  
Angle Scattering
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