SEM and TEM Characterization of Magnesium Hydride Catalyzed with Ni Nano-Particle or Nb2O5

Hanada Nobuko

Enoki Hirotoshi

Ichikawa Takayuki

Akiba Etsuo

Fujii Hironobu

Journal of Alloys and Compounds

The microstructures of MgH2 catalyzed with Ni nano-particle or Nb2O5 mesoporous powders are examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations. For MgH2 catalyzed with Ni, the Ni particles with the diameter smaller than 1 μm were detected on the MgH2 particles with the diameter smaller than 5 μm by the back scattering electron (BSE) microscopy. In details, the TEM micrograph indicates that the Ni particles distribute ~20 nm in diameter on MgH2 uniformly, which was the same size as the additive doped in MgH2 before milling. On the other hand, for MgH2 catalyzed with Nb2O5, the additive particles could not be found anywhere in the BSE image. Even in the TEM micrograph by much larger magnification than the SEM micrograph, the particles corresponding to the additive can not be observed at all. Furthermore, an energy dispersive X-ray (EDX) analysis in spots with a diameter of 20 nm indicated that the existing ratio of Mg to Nb was evaluated to 98:2, being the same as the starting ratio before milling. Therefore, the metal oxide Nb2O5 becomes extremely small particle that could not be observed by the present work after milling compared to metal Ninano.

hydrogen absorbing materials

ball-milling

microstructure

scanning electron microscopy

SEM

transmission electron microscopy

TEM

Physics [ 420 ]

eng

Elsevier B.V.

Copyright (c) 2006 Elsevier B.V.

[NCID] AA10817249

[ISSN] 0925-8388

[DOI] 10.1016/j.jallcom.2006.10.128

[DOI] http://doi.org/10.1016/j.jallcom.2006.10.128