“…Therefore, if the sample is pre-pulverized by mechanical means to have a particle size below that observed after a number of hydriding cycles, for example, less than 20 m, it is anticipated that the degradation of hydrogen storage capacity arising from embrittlement may be suppressed. A dramatic decrease in dislocation density near the surface of the particles is frequently observed by TEM in the pre-pulverized samples [11]. Also, from the SEM observation, pre-pulverized samples contain few cracks after an appropriate annealing.…”