Atomic scale diffusion dynamics of hydrogen in deep-Earth minerals by pulsed neutron scattering

这一年的研究成果包括准弹性中子散射(QENS)和单晶中子衍射(SCND)两个系列的中子散射实验结果。密度水合硅酸镁(DHMS)相E相氢的QENS分析是在BL2的MLF，J-PARC进行的。去年在橡树岭国家实验室散裂中子源的BL12上进行了全氚DHMS相E相晶体的SCND测量。今年，通过对获得的衍射数据进行系统分析，我们在空间上以很高的分辨率(dmin=0.5)完全解析了它的晶体结构。测定并公布了重氢的位置、化学键几何构型以及掺入晶体结构的机理。我们在国内和国际会议上作了几次发言，介绍了所描述的结果和进展。

The research achevements in this year consisted of two series of neutron scattering experimental results, which are quasielastic neutron scattering (QENS) and single crystal neutron diffraction (SCND). The QENS analysis of hydrogen in dense hydrous magnesium silicate (DHMS) phase E was conducted at BL2 at MLF, J-PARC. Atomic-scale diffusion dynamics of hydrogen was successfully determined as a function of temperature up to 530 K. The SCND measurement of a fully-deuterated DHMS phase E crystal was conducted at BL12 at Spallation Neutron Source, Oak Ridge National Laboratory in last year. This year, by systematically analyzing the obtained diffraction dataset, we fully resolved its crystal structure with very high resolution in space (dmin =0.5). The site position of deuterium, its chemical bonding geometry, as well as its incorporation mechanism into the crystal structure were deterimned and published. We made a few presentations in domestic and international meetings to present the described results and progress.