Comparison of Graphites Intercalated with Fluorine as Slow Neutron Reflectors.

The use of neutron reflectors is an effective method for improving the quality of neutron sources and neutron delivery systems. In this work, we further develop the method based on the Bragg scattering of neutrons in crystals with large interplanar distances. We compare samples of differently prepared fluorine intercalated graphites by measuring the total cross section for the interaction of neutrons with the samples, depending on the neutron wavelength.

Flexible fluorinated graphite foils with high contents of the (CF) phase for slow neutron reflectors.

In order to prepare self-standing and flexible slow neutron reflectors made of graphite fluoride (GF) with high contents of (CF) structural phase, graphite foils of different thicknesses were used as starting materials for gas (F)/solid fluorination. The maximal interlayer distance of GF was obtained with this phase thanks to the stacking sequence FCCF/FCCF; this is mandatory for the efficient reflection of slow neutrons. 71 and 77% of the (CF) phase were achieved for graphite foils with thicknesses of 1.

In-depth investigations of size and occupancies in cobalt ferrite nanoparticles by joint Rietveld refinements of X-ray and neutron powder diffraction data.

Powder X-ray diffraction (PXRD) and neutron powder diffraction (NPD) have been used to investigate the crystal structure of CoFeO nanoparticles prepared different hydro-thermal synthesis routes, with particular attention given to accurately determining the spinel inversion degrees. The study is divided into four parts. In the first part, the investigations focus on the influence of using different diffraction pattern combinations (NPD, Cu-source PXRD and Co-source PXRD) for the structural modelling.