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Microstructure of MmM 5 /Mg multi‐layer hydrogen storage films prepared by magnetron sputtering
Author(s) -
Ouyang L.Z.,
Wang H.,
Zhu M.,
Zou J.,
Chung C.Y.
Publication year - 2004
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.20089
Subject(s) - nanocrystalline material , crystallite , amorphous solid , materials science , microstructure , sputter deposition , layer (electronics) , transmission electron microscopy , thin film , mischmetal , sputtering , analytical chemistry (journal) , composite material , crystallography , metallurgy , nanotechnology , hydrogen storage , chemistry , chromatography , alloy
Multi‐layer hydrogen storage thin films with Mg and MmNi 3.5 (CoAlMn) 1.5 (here Mm denotes La‐rich mischmetal) as alternative layers were prepared by direct current magnetron sputtering. Transmission electron microscopy investigation shows that the microstructure of the MmNi 3.5 (CoAlMn) 1.5 and Mg layers are significantly different although their deposition conditions are the same. The MmNi 3.5 (CoAlMn) 1.5 layer is composed of two regions: one is an amorphous region approximately 4 nm thick at the bottom of the layer and the other is a nanocrystalline region on top of the amorphous region. The Mg layer is also composed of two regions: one is a randomly orientated nanocrystalline region 50 nm thick at the bottom of the layer and the other is a columnar crystallite region on top of the nanocrystalline region. These Mg columnar crystallites have their [001] directions parallel to the growth direction and the average lateral size of these columnar crystallites is about 100 nm. A growth mechanism of the multi‐layer thin films is discussed based on the experiment results. Microsc. Res. Tech. 64:323–329, 2004. © 2004 Wiley‐Liss, Inc.