TY - JOUR
T1 - Distribution of hydrogen in metal hydrides studied by in situ powder neutron diffraction
AU - Nakamura, Yumiko
AU - Nakamura, Jin
AU - Iwase, Kenji
AU - Akiba, Etsuo
N1 - Funding Information:
Part of this work was supported by the New Energy and Industrial Technology Development Organization (NEDO) under Advanced Fundamental Research on Hydrogen Storage Materials (HYDRO-STAR). The authors thank Dr. R.C. Bowman, Jr. and Dr. H. Hayakawa for providing alloy samples, and Dr. F. Izumi for providing and tuning RIETAN-TN. They are thankful for technical assistance with neutron diffraction experiments from the Vega and Sirius team at KENS.
Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2009/2/21
Y1 - 2009/2/21
N2 - Interstitial metal hydrides were studied by in situ powder neutron diffraction for their use in hydrogen storage. The main focus was the distribution of hydrogen atoms in the materials. In full hydrides of LaNi5-xAlx, hydrogen occupation depended strongly on the amount of Al. The symmetry varied from P63mc (x=0) to P6mm (x=0.1) and P6/mmm (x≥0.25) with change in occupancy of each site. Variation in hydrogen occupation during absorption and desorption was analyzed for LaNi4.78Sn0.22. Redistribution between three tetrahedral sites was observed during desorption. La5Ni19-based hydrides with a structure consisting of stacking La2Ni4 and LaNi5 cells were also studied. Rietveld refinement of La4MgNi19D∼24 showed that hydrogen distributed almost evenly in LaMgNi4 and LaNi5 cells (0.8-1.0 H/M), which was consistent with the uniform lattice expansion of those cells. This result indicated that substitution of Mg for La changed the preferred sites for hydrogen occupation in the La2Ni4 and LaNi5 cells.
AB - Interstitial metal hydrides were studied by in situ powder neutron diffraction for their use in hydrogen storage. The main focus was the distribution of hydrogen atoms in the materials. In full hydrides of LaNi5-xAlx, hydrogen occupation depended strongly on the amount of Al. The symmetry varied from P63mc (x=0) to P6mm (x=0.1) and P6/mmm (x≥0.25) with change in occupancy of each site. Variation in hydrogen occupation during absorption and desorption was analyzed for LaNi4.78Sn0.22. Redistribution between three tetrahedral sites was observed during desorption. La5Ni19-based hydrides with a structure consisting of stacking La2Ni4 and LaNi5 cells were also studied. Rietveld refinement of La4MgNi19D∼24 showed that hydrogen distributed almost evenly in LaMgNi4 and LaNi5 cells (0.8-1.0 H/M), which was consistent with the uniform lattice expansion of those cells. This result indicated that substitution of Mg for La changed the preferred sites for hydrogen occupation in the La2Ni4 and LaNi5 cells.
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U2 - 10.1016/j.nima.2008.11.128
DO - 10.1016/j.nima.2008.11.128
M3 - Article
AN - SCOPUS:59649115375
SN - 0168-9002
VL - 600
SP - 297
EP - 300
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 1
ER -