Stable Compositions, Structures and Electronic Properties in K–Ga Systems Under Pressure  

作　　者：Chao Wang Yun-Xian Liu Xin Chen Pin Lv Hai-Rui Sun Xiao-Bing Liu 王超;刘云仙;陈欣;吕品;孙海瑞;刘晓兵(Laboratory of High Pressure Physics and Material Science,School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165)

机构地区：[1]Laboratory of High Pressure Physics and Material Science,School of Physics and Physical Engineering,Qufu Normal University,Qufu 273165

出　　处：《Chinese Physics Letters》2020年第2期39-42,共4页中国物理快报（英文版）

基　　金：the Shandong-Provincial Science Foundation(ZR2018PA010,ZR2017BA020,ZR2017BA012,ZR2019MA054 and 2019KJJ020);the National Natural Science Foundation of China(11704220,11674122,11804184,1180418 and 11974208).

摘　　要：New stable stoichiometries in K-Ga systems are firstly investigated up to 100 GPa by the unbiased structure searching techniques.Six novel compositions as K4Ga,K3Ga,K2Ga,KGa,KGa2 and KGa4 are found to be thermodynamically stable under pressure.Most of the predicted stable phases exhibit metallic character,while the Fd3m KGa phase behaves as a semiconductor with a bandgap ~1.62 eV.Notably,the gallium atoms exhibit different interesting morphologies;e.g.,Ga2 units,zigzag chains,six rings and cage.We further investigate the bonding nature of K-Ga systems with help of electron localization function and Bader charge analyses.Strong covalent bonding characteristics are found between the Ga and Ga atoms,and ionic bonding patterns are observed between the K and Ga atoms.Meanwhile,we notice charge transferring from the K atom to the Ga atom in the K-Ga systems.The present results can be helpful for understanding the diverse structures and properties of K-Ga binary compounds at high pressures.

关 键 词：BONDING CHARGE CHAINS 

分 类 号：O481[理学—固体物理]