TY - JOUR
T1 - Crystal structural studies of AB5-type, BCC and Zintl phase hydrogen absorbing alloys
AU - Akiba, Etsuo
AU - Enoki, Hirotoshi
AU - Nakamura, Yumiko
PY - 2002/6/1
Y1 - 2002/6/1
N2 - Our progress on crystal structural studies on hydrogen absorbing alloys including intermetallics and solid solutions is reviewed. LaNi5 shows an extremely high equilibrium pressure at the first hydrogen absorption, but not at the second one. The structural change in the first absorption was followed by in situ X-ray diffraction. We found that the crystalline size did not change but the anistropic strain was introduced to the lattice of the hydride formed. The strain introduced was not relaxed in the following dehydrogenation and hydrogenation. However, the behavior of LaNi4.75Al0.25 for the first absorption was completely different from LaNi5. The strain observed for LaNi5 was not found at the first absorption but a reversible stain parallel to the c-axis was observed in desorption. The crystal structure of Laves phase related BCC alloys and their hydrides was refined by the Rietveld method using in-situ X-ray and neutron powder diffraction data. It was confirmed that these alloys had BCC structure, which means constituent elements occupy the BCC sites randomly. A new class of hydride with Zintl anion was found and the crystal structure of hydride/deuteride was refined using neutron diffraction.
AB - Our progress on crystal structural studies on hydrogen absorbing alloys including intermetallics and solid solutions is reviewed. LaNi5 shows an extremely high equilibrium pressure at the first hydrogen absorption, but not at the second one. The structural change in the first absorption was followed by in situ X-ray diffraction. We found that the crystalline size did not change but the anistropic strain was introduced to the lattice of the hydride formed. The strain introduced was not relaxed in the following dehydrogenation and hydrogenation. However, the behavior of LaNi4.75Al0.25 for the first absorption was completely different from LaNi5. The strain observed for LaNi5 was not found at the first absorption but a reversible stain parallel to the c-axis was observed in desorption. The crystal structure of Laves phase related BCC alloys and their hydrides was refined by the Rietveld method using in-situ X-ray and neutron powder diffraction data. It was confirmed that these alloys had BCC structure, which means constituent elements occupy the BCC sites randomly. A new class of hydride with Zintl anion was found and the crystal structure of hydride/deuteride was refined using neutron diffraction.
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U2 - 10.1016/S0921-5093(01)01591-X
DO - 10.1016/S0921-5093(01)01591-X
M3 - Article
AN - SCOPUS:0036601146
VL - 329-331
SP - 321
EP - 324
JO - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
JF - Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing
SN - 0921-5093
ER -