高強度中性子全散乱装置NOVAによる水素貯蔵材料の構造解析

抄録

Abstract: It is common and fundamental technique for developments of hydrogen storage materials to investigate atomic arrangements of hydrogen during the absorption and desorption process. Since neutron is sensitive probe against hydrogen, the structural environment of hydrogen in atomic scale is clarified by neutron scattering method. High intensity total diffractometer, NOVA, was constructed in the pulsed neutron facility of Japan Proton Accelerator Research Complex (J-PARC). The most characteristic feature of NOVA is that it covers a wide scale of atomic distance from nearest neighbor to several ten nano meters by wide-Q (momentum transfer) measurement in short-time. By Fourier transformation of the obtained wide-Q diffraction data, Pair Distribution Function (PDF) useful for the analysis of disordered structures can be derived with high real-space resolution. On NOVA, both the wide-d space crystal structure analysis (Rietveld analysis) and the high-resolution PDF analysis can be performed. This means that various structures of crystals, amorphous and liquids for hydrogen storage materials are elucidated with NOVA. Aluminum hydride, Lanthanum hydride under GPa pressure and so on have been analyzed. Furthermore, time-transient measurement during hydrogen absorption and desorption process under hydrogen gas atmosphere (max 10 MPa) have been equipped on NOVA. It is expecting that structural analysis with NOVA will accelerate developments of hydrogen storage materials by industries.