Local electronic structure of interstitial hydrogen in MgH2 inferred from muon study
Local electronic structure of interstitial hydrogen in MgH2 inferred from muon study
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从μ子研究推断出MgH2中间隙氢的局域电子结构
DOI：
10.1088/1361-648x/acccc7
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Ito Takashi U.
中科院分区：
文献类型：
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作者：
Kadono Ryosuke;Hiraishi Masatoshi;Okabe Hirotaka;Koda Akihiro;Ito Takashi U.
氢化镁具有7.6wt%的高贮氢容量，是一种很有潜力的固体贮氢材料。然而，其缓慢的氢化和脱氢动力学以及分解所需的300 ℃高温是汽车等小规模应用的主要障碍。MgH 2中间隙氢的局域电子结构是解决这一问题的重要基础知识，目前主要基于密度泛函理论（DFT）对其进行了研究。然而，很少有实验研究已经进行了评估DFT计算的结果。因此，我们在MgH 2中引入了μ子作为赝H，并详细研究了相应的间隙H态的电子和动力学性质.因此，我们观察到多个Mu状态类似于在宽禁带氧化物中观察到的，并发现它们的电子状态可以归因于最近提出的“双极性模型”预测的与施主/受主能级相关的弛豫激发态。这为DFT计算提供了间接支持，该模型是基于通过供体/受体水平。μ介子结果对于改进氢动力学的一个重要意义是，脱氢作为还原氢的还原剂，稳定了间隙H−态。
Magnesium hydride has great potential as a solid hydrogen (H) storage material because of its high H storage capacity of 7.6 wt%. However, its slow hydrogenation and dehydrogenation kinetics and the high temperature of 300∘ C required for decomposition are major obstacles to small-scale applications such as automobiles. The local electronic structure of interstitial H in MgH 2 is an important fundamental knowledge in solving this problem, which has been studied mainly based on density functional theory (DFT). However, few experimental studies have been performed to assess the results of DFT calculations. We have therefore introduced muon (Mu) as pseudo-H into MgH 2 and investigated the corresponding interstitial H states by analyzing their electronic and dynamical properties in detail. As a result, we observed multiple Mu states similar to those observed in wide-gap oxides, and found that their electronic states can be attributed to relaxed–excited states associated with donor/acceptor levels predicted by the recently proposed'ambipolarity model'. This provides an indirect support for the DFT calculations on which the model is based via the donor/acceptor levels. An important implication of the muon results for improved hydrogen kinetics is that dehydrogenation, serving as a reduction for hydrides, stabilises the interstitial H− state.
μ子和μ化学：μSR数据的分析和解释
DOI：
10.1017/cbo9780511721717.007
发表时间：
1983
期刊：
The Review of scientific instruments
影响因子：
--
作者：
D. Walker
通讯作者：
D. Walker
DOI：
--
发表时间：
2021
期刊：
影响因子：
--
作者：
H. Okabe;M. Hiraishi;A. Koda;R. Kadono;T. Ohsawa;N. Ohashi
通讯作者：
N. Ohashi