Ab initio investigation of structures, electronic and thermodynamic properties for Li–Mg–H ternary system
Ab initio investigation of structures, electronic and thermodynamic properties for Li–Mg–H ternary system
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DOI：
10.1016/j.jallcom.2011.05.084
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发表时间：
2011-08
影响因子：
6.2
通讯作者：
Daixin Li;Tianran Zhang;Siqi Yang;Zhanliang Tao;Jun Chen
中科院分区：
文献类型：
--
作者：
Daixin Li;Tianran Zhang;Siqi Yang;Zhanliang Tao;Jun Chen
A systematic consideration of the compounds made up of Li, Mg and H has been taken with respect to the structural, electronic, and thermodynamic properties, by means of density functional theory (DFT). Through the database mining approach, the ground state structures of LiMgH3and Li2MgH4are identified to beR3candPbam, respectively. The Li–Mg–H ternary hydrides are insulators dominated by ionic bonds besides some covalent components between Mg and H. Energies of different formation pathways have been calculated at finite temperature. Hydrides synthesized from Li, Mg and H2possess obvious energetic advantage, but may be inhabited kinetically by pure phase separation. Thermodynamically reversible decomposition to LiH and MgH2brings about another issue for the actual preparation and stable existence of the ternary hydrides. Inserting H atoms to the sites of the ordered alloys with high electric density has been taken as another way to explore possible structures of this system. As H uptakes stepwise, the resulted compounds turn from conductors to insulators. The present results shed light on the design of Li–Mg–H ternary hydrides.
