Powder neutron diffraction study of phase E

Abstract

The crystal structure of phase E, which is one of dense hydrous magnesian silicates, was previously clarified based on single crystal X-ray diffraction, however hydrogen positions are yet to be determined. In this study, a large volume cell assembly has been developed for powder neutron diffraction and ~70 mg of the phase E powder was successfully synthesized at 15 GPa and 1100°C. The positions and site occupancies of D atoms in the phase E structure refined by the Rietveld analysis of obtained neutron diffraction pattern will be discussed.