Crystal structures and hydrogenation–dehydrogenation characteristics of Er(Ni1−xMnx)2
Crystal structures and hydrogenation–dehydrogenation characteristics of Er(Ni1−xMnx)2
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DOI：
10.1016/j.jallcom.2014.11.157
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发表时间：
2015-03
影响因子：
6.2
通讯作者：
Q. Zhang;Z. Dong;S. Xie
中科院分区：
文献类型：
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作者：
Q. Zhang;Z. Dong;S. Xie
本工作研究了 Er(Ni1−xMnx)2 化合物的晶体结构和加氢-脱氢特性。研究发现，退火或氢化都会导致ErNi2从MgCu2型结构有序转变为TmNi2型超结构。由于Mn含量在x= 0.2–0.8和0.9–1范围内，Er(Ni1−xMnx)2化合物分别具有C15和C14结构。随着Mn含量x的增加，C15型Er(Ni1-xMnx)2的吸氢量增加，但吸收平台压力逐渐降低，氢脱附变得困难。 ErMn2在3.5×10−5和1.5×10−1MPa下分别吸收氢形成不可逆的ErMn2H3.4和可逆的ErMn2H4.8。然而，C14型Er(Ni0.1Mn0.9)2化合物在吸氢过程中分解成ErMn2Hz和ErNi2Hy。
The crystal structures and hydrogenation–dehydrogenation characteristics of Er(Ni1−xMnx)2compounds are investigated in this work. It is found that either annealing or hydrogenation leads to ordering transition of ErNi2from MgCu2-type structure to TmNi2-type superstructure. As Mn content is withinx= 0.2–0.8 and 0.9–1, Er(Ni1−xMnx)2compounds have C15 and C14 structures, respectively. The hydrogen absorption content of the C15-type Er(Ni1−xMnx)2increases with raising Mn contentx, however, the absorption plateau pressure decreases gradually and hydrogen desorption becomes difficult. ErMn2can absorb hydrogen to form irreversible ErMn2H3.4and reversible ErMn2H4.8at 3.5 × 10−5and 1.5 × 10−1MPa, respectively. Nevertheless, the C14-type Er(Ni0.1Mn0.9)2compound is subjected to decomposition into ErMn2Hzand ErNi2Hyduring hydrogen absorption.