| Autor: |
Soloninin, Alexei V., Skripov, Alexander V., Babanova, Olga A., Morozova, Olga S., Leonov, Alexander V. |
| Zdroj: |
The Journal of Physical Chemistry - Part C; January 2010, Vol. 114 Issue: 1 p646-651, 6p |
| Abstrakt: |
To study the effects of ball milling on hydrogen mobility in TiH2with C, B, and BN additives, we have measured the 1H and 11B nuclear magnetic resonance (NMR) spectra and spin−lattice relaxation rates in these nanostructured systems over the temperature range 11−384 K. It is found that for the ball-milled TiH2without any additives and with C and B additives, the hydrogen jump rates remain to be below ∼105s−1up to 384 K. The mobility of H atoms in the ball-milled TiH2with BN additive is found to be much higher than that in the other studied TiH2-based systems. Our experimental results for the ball-milled TiH2/BN suggest a coexistence of two H jump processes: the fast localized motion with the characteristic H jump rate of about 2 × 108s−1at 170 K and the slower long-range H diffusion responsible for the strong narrowing of the 1H NMR line at T> 250 K and the frequency-dependent rise of the spin−lattice relaxation rate at T> 320 K. The acceleration of H motion in the ball-milled TiH2/BN may be related to interstitial N atoms appearing in the distorted TiH2grains in the process of ball milling. |
| Databáze: |
Supplemental Index |
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