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.