TY - JOUR
T1 - Effect of Mg/Ni ratio on microstructure of Mg-Ni films deposited by magnetron sputtering
AU - Matsuda, Junko
AU - Uchiyama, Naoki
AU - Kanai, Tomomi
AU - Harada, Kazumi
AU - Akiba, Etsuo
N1 - Funding Information:
The author(s) gratefully acknowledge the support of the International Institute for Carbon Neutral Energy Research (WPI–I2CNER), sponsored by the Japanese Ministry of Education, Culture, Sports, Science and Technology , (MEXT). This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO) – Japan.
PY - 2014/12/25
Y1 - 2014/12/25
N2 - The relationship between the Mg/Ni ratio and microstructure of Mg-Ni films with a Pd-cap deposited by magnetron sputtering is investigated using transmission electron microscopy. As a result, the 6Mg-Ni films are observed to be composed of a Mg-rich amorphous matrix and Mg2Ni nanocrystals. In contrast, the 10Mg-Ni films contain Mg nanocrystals and Mg-rich amorphous. The 2Mg-Ni films, which absorb/desorb hydrogen repeatedly as well as 6Mg-Ni films, are fully amorphous and have a homogeneous distribution of Mg and Ni. The hydrogenated 6Mg-Ni film, after 200 cycles of hydrogenation/dehydrogenation, includes Mg2NiH4 and MgH2 nanocrystals as well as Mg crystals. In conclusion, the crystallization of Mg reduces desorption kinetics and cycle ability of the Mg-Ni films. Our results suggested that Mg crystallization occurs in films with an initial Mg/Ni ratio greater than 7.7 the eutectic composition between Mg and Mg2Ni.
AB - The relationship between the Mg/Ni ratio and microstructure of Mg-Ni films with a Pd-cap deposited by magnetron sputtering is investigated using transmission electron microscopy. As a result, the 6Mg-Ni films are observed to be composed of a Mg-rich amorphous matrix and Mg2Ni nanocrystals. In contrast, the 10Mg-Ni films contain Mg nanocrystals and Mg-rich amorphous. The 2Mg-Ni films, which absorb/desorb hydrogen repeatedly as well as 6Mg-Ni films, are fully amorphous and have a homogeneous distribution of Mg and Ni. The hydrogenated 6Mg-Ni film, after 200 cycles of hydrogenation/dehydrogenation, includes Mg2NiH4 and MgH2 nanocrystals as well as Mg crystals. In conclusion, the crystallization of Mg reduces desorption kinetics and cycle ability of the Mg-Ni films. Our results suggested that Mg crystallization occurs in films with an initial Mg/Ni ratio greater than 7.7 the eutectic composition between Mg and Mg2Ni.
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U2 - 10.1016/j.jallcom.2014.07.201
DO - 10.1016/j.jallcom.2014.07.201
M3 - Article
AN - SCOPUS:84906350941
VL - 617
SP - 47
EP - 51
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -