Electronic structures and thermodynamic stabilities of aluminum-based deuterides from first principles calculations  

作　　者：叶小球 罗德礼 桑革 敖冰云 

机构地区：[1]Science and Technology on Surface Physics and Chemistry Laboratory

出　　处：《Chinese Physics B》2011年第1期534-540,共7页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.20971114)

摘　　要：The alanates （complex aluminohydrides） have relatively high gravimetric hydrogen densities and are among the most promising solid-state hydrogen-storage materials. In this work, the electronic structures and the formation enthalpies of seven typical aluminum-based deuterides have been calculated by the plane-wave pseudopotential method, these being A1D3, LiA1D4, Li3A1D6, BaA1D5, Ba2A1D7, LiMg（A1D4）3 and LiMgA1D6. The results show that all these compounds are large band gap insulators at 0 K with estimated band gaps from 2.31 eV in A1D3 to 4.96 eV in LiMg（A1D4）3. The band gaps are reduced when the coordination of A1 varies from 4 to 6. Two peaks present in the valence bands are the common characteristics of aluminum-based deuterides containing A1D4 subunits while three peaks are the common characteristics of those containing A1D6 subunits. The electronic structures of these compounds are determined mainly by aluminum deuteride complexes （A1D4 or A1D6） and their mutual interactions. The predicted formation enthalpies are presented for the studied aluminum-based deuterides.The alanates （complex aluminohydrides） have relatively high gravimetric hydrogen densities and are among the most promising solid-state hydrogen-storage materials. In this work, the electronic structures and the formation enthalpies of seven typical aluminum-based deuterides have been calculated by the plane-wave pseudopotential method, these being A1D3, LiA1D4, Li3A1D6, BaA1D5, Ba2A1D7, LiMg（A1D4）3 and LiMgA1D6. The results show that all these compounds are large band gap insulators at 0 K with estimated band gaps from 2.31 eV in A1D3 to 4.96 eV in LiMg（A1D4）3. The band gaps are reduced when the coordination of A1 varies from 4 to 6. Two peaks present in the valence bands are the common characteristics of aluminum-based deuterides containing A1D4 subunits while three peaks are the common characteristics of those containing A1D6 subunits. The electronic structures of these compounds are determined mainly by aluminum deuteride complexes （A1D4 or A1D6） and their mutual interactions. The predicted formation enthalpies are presented for the studied aluminum-based deuterides.

关 键 词：hydrogen storage material complex aluminohydrides electronic structures density functional theory 

分 类 号：O469[理学—凝聚态物理]