NMR study of the nanocrystalline palladium–hydrogen system
NMR study of the nanocrystalline palladium–hydrogen system
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纳米晶钯-氢体系的核磁共振研究
DOI：
10.1016/s0925-8388(01)01498-0
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发表时间：
2002
影响因子：
6.2
通讯作者：
J. Eastman
中科院分区：
文献类型：
--
作者：
J. Hanneken;D. Baker;M. Conradi;J. Eastman
室温下纳米晶n-PdH0.7的质子核磁共振谱显示出两个明显的、运动变窄的峰，这两个峰归因于微晶间隙和界面氢布居。此外，质子自旋-晶格弛豫测量显示弛豫速率增强。这两个结果与先前观察到的α相n-PdHx晶界氢气浓度的增加是定性一致的。N-PdH0.7的磁化恢复数据还表明，氢的独立布居不会在0.1级的S的时间尺度上交换，这是一个令人惊讶的结果，考虑到与自旋-晶格驰豫相关的关联时间，10−8s。
Proton nuclear magnetic resonance spectra of nanocrystalline n-PdH0.7at room temperature reveal two distinct, motionally-narrowed peaks, attributed to crystallite interstitial and interfacial hydrogen populations. In addition, proton spin-lattice relaxation measurements show enhanced relaxation rates. Both results are qualitatively consistent with a previously-observed hydrogen concentration enhancement in grain boundaries of α-phase n-PdHx. Magnetization recovery data for n-PdH0.7also reveal that the separate populations of hydrogen do not exchange on time scales of up to order 0.1 s, a surprising result considering the correlation time associated with spin-lattice relaxation, of order 10−8s.