Observation of the defects induced by hydrogen absorption and desorption in LaNi5

Strain formation and lattice parameter change in LaNi4.75Sn0.25–H system during the initial activation process

“…This indicates that the hydriding reaction at ambient temperature possibly induces large disorder in the atomic configuration to generate lattice defects. Actually, introduction of high density of lattice defects, such as dislocations and vacancies during the first hydriding reaction has been observed [3][4][5][6].…”

Effects of ion irradiation on hydriding rate of Mm based hydrogen storage alloy

“…Hydrogen trapping sites act as the center of segregation of hydrides even in hydrogen solid-solution region [12]. Oxide/metal interfaces also tend to act as hydrogen trapping sites and form hydrides in the course of hydrogen absorption, and a marked effect of surface oxidation on the hydriding kinetics of La-Ni based hydrogen absorbing alloys was reported [12][13][14]. Based on these facts, we intentionally induced vacancies with high concentrations by ion irradiation in the surface region of alloys, and investigated the effects of the vacancy formation on the initial rate of hydrogen absorption by MmNi 5 .…”

“…The hydrogen trapping effects, for example, induce a marked increase in the hydrogen solubility and the heat of hydrogen solution of alloy [11]. Hydrogen trapping sites act as the center of segregation of hydrides even in hydrogen solid-solution region [12]. Oxide/metal interfaces also tend to act as hydrogen trapping sites and form hydrides in the course of hydrogen absorption, and a marked effect of surface oxidation on the hydriding kinetics of La-Ni based hydrogen absorbing alloys was reported [12][13][14].…”

Formation of lattice strain in MmNi4.30-xCoxAl0.30Mn0.40MmNi4.30-xCoxAl0.30Mn0.40 (x=0,0.75)(x=0,0.75) during hydrogenation

“…TEM is an effective method to determine the type and geometry of lattice defects by direct observation [21][22][23], while it provides information about only local areas selected in the sample. On the other hand, X-ray and neutron diffraction can give average information about crystal lattice of the sample.…”