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

本年度的研究成果包括两个系列的中子散射实验结果，即准弹性中子散射（QENS）和单晶中子衍射（SCND）。在J-PARC MLF的BL2下对致密水合硅酸镁（DHMS） E相中的氢进行了QENS分析。成功地确定了氢的原子尺度扩散动力学作为温度高达530 K的函数。去年在美国橡树岭国家实验室散裂中子源BL12对全氘化DHMS相E晶体进行了SCND测量。今年，通过系统分析获得的衍射数据集，我们以非常高的空间分辨率（dmin =0.5）完全解析了其晶体结构。测定并发表了氘的位置、化学键的几何形状及其在晶体结构中的结合机理。我们在国内和国际会议上做了一些介绍，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.