Thermodynamical stability and electronic structure of a perovskite-type hydride, NaMgH3
Thermodynamical stability and electronic structure of a perovskite-type hydride, NaMgH3
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DOI：
10.1016/j.jallcom.2007.03.093
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发表时间：
2007-10
影响因子：
6.2
通讯作者：
K. Ikeda;S. Kato;Y. Shinzato;N. Okuda;Y. Nakamori;A. Kitano;H. Yukawa;M. Morinaga;S. Orimo
中科院分区：
文献类型：
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作者：
K. Ikeda;S. Kato;Y. Shinzato;N. Okuda;Y. Nakamori;A. Kitano;H. Yukawa;M. Morinaga;S. Orimo
实验研究了具有可逆分解和复合反应的钙钛矿型氢化物NaMgH 3的热力学稳定性和电子结构。NaMgH 3的分解伴随着氢的脱附反应，分解过程分两步进行，第一步的焓变（ΔH）和熵变（ΔS）分别为ΔH（1）=−93.9（6）kJ/molH 2和ΔS（1）=−116.2（9）J/KmolH 2;第二步的焓变（Δ H）和熵变（Δ S）分别为ΔH（2）=−102.2（4）kJ/molH 2和ΔS（2）=−125.9（6）J/KmolH 2。最大熵法（MEM）/Rietveld分析的同步辐射X射线衍射曲线表明，NaMgH 3含有两个氢负离子在不同的占领网站。
Thermodynamical stability and electronic structure of a perovskite-type hydride, NaMgH3, exhibiting reversible decomposition and recombination reactions, were studied experimentally. NaMgH3decomposes in two steps accompanying hydrogen desorption reactions, and the enthalpy change (ΔH) and the entropy change (ΔS) are calculated to be ΔH(1)=−93.9(6)kJ/molH2and ΔS(1)=−116.2(9)J/KmolH2for the first step, and ΔH(2)=−102.2(4)kJ/molH2and ΔS(2)=−125.9(6) J/KmolH2for the second step, respectively. Maximum entropy method (MEM)/Rietveld analysis of synchrotron X-ray diffraction profiles indicated that NaMgH3contains two hydrogen anions at the different occupation sites.