In situ X-ray and neutron powder diffraction study of LaNi_(5-x)Sn_x-H systems

摘要

We have studied structural change and lattice strain formation during absorption and desorption of hydrogen (deuterium) by high purity LaNi_(5-x)Sn_x alloys (x = 0.22, 0.25) using in situ X-ray and neutron diffraction along with simultaneously measuring the P-C isotherms. From profile analysis of the X-ray diffraction data, lattice parameter and lattice strain in each hydriding state are evaluated. In situ neutron diffraction data provided hydrogen occupation changing with hydrogen content. Significant lattice contract and strain formation were observed in the hydride phase in desorption. This behavior was related with decrease in hydrogen occupation in the hydride phase revealed from the neutron diffraction data.