TY - JOUR
T1 - Effect of substitutional Cr on hydrogen diffusion and thermal stability for the BCT monohydride phase of the V-H system studied by 1H NMR
AU - Asano, Kohta
AU - Hayashi, Shigenobu
AU - Nakamura, Yumiko
AU - Akiba, Etsuo
N1 - Funding Information:
The authors would like to thank Dr. Y. Suzuki of National Institute of Advanced Industrial Science and Technology (AIST) for his technical advices on NMR. This work was supported by the New Energy and Industrial Technology Development Organization (NEDO) under “ Advanced Fundamental Research on Hydrogen Storage Materials (Hydro-Star) ”.
PY - 2012/5/25
Y1 - 2012/5/25
N2 - The diffusion of hydrogen in the monohydride phase (β phase) of the V 1-xCr x-H (x ≤ 0.1) system was studied by means of 1H nuclear magnetic resonance (NMR). Hydrogen atoms in the hydrides occupied the octahedral (O) sites in a body centered tetragonal (BCT) structure. The BCT lattice was contracted by addition of Cr because Cr has a smaller atomic radius than V. The activation energy for hydrogen diffusion, E H, and the Korringa constant, T 1eT, were estimated from the temperature and frequency dependence of 1H spin-lattice relaxation times, T 1. The value of E H increased with increase in the Cr content. The contraction of the BCT lattice by addition of Cr suppressed the diffusion of hydrogen which occupied the interstitial sites. Addition of Cr also increased the T 1eT, which was accompanied by reducing in the stability of the monohydride phase of the V-H system.
AB - The diffusion of hydrogen in the monohydride phase (β phase) of the V 1-xCr x-H (x ≤ 0.1) system was studied by means of 1H nuclear magnetic resonance (NMR). Hydrogen atoms in the hydrides occupied the octahedral (O) sites in a body centered tetragonal (BCT) structure. The BCT lattice was contracted by addition of Cr because Cr has a smaller atomic radius than V. The activation energy for hydrogen diffusion, E H, and the Korringa constant, T 1eT, were estimated from the temperature and frequency dependence of 1H spin-lattice relaxation times, T 1. The value of E H increased with increase in the Cr content. The contraction of the BCT lattice by addition of Cr suppressed the diffusion of hydrogen which occupied the interstitial sites. Addition of Cr also increased the T 1eT, which was accompanied by reducing in the stability of the monohydride phase of the V-H system.
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U2 - 10.1016/j.jallcom.2012.01.137
DO - 10.1016/j.jallcom.2012.01.137
M3 - Article
AN - SCOPUS:84857667063
VL - 524
SP - 63
EP - 68
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
SN - 0925-8388
ER -