Substitution Effects on MgB2 Superconductivity  

作　　者：LIU Juan ZHAO Yuan YI Lin 

机构地区：[1]Department of Physics, Huazhong University of Science and Technology, Wuhan 430074, China

出　　处：《Communications in Theoretical Physics》2008年第2期504-506,共3页理论物理通讯（英文版）

基　　金：Natural Science Foundation of Hubei Province of China under Grant No.2007ABA035

摘　　要：With the help of supercell method, the first-principle calculations were performed for the study of doping crystal Mg1-xAlxB2 and Mg（B1-yCy）2. Analyzing the variations of the charge distribution and the partial densities of states, we found that the compounds with doping Al to MgB2 compound and/or replacing boron by carbon exhibit new covalent bond effects and unexpected electronic properties, related to superconductivity. The study of the density of states indicates that superconductivity decreases with the increase of Al fraction and carbon concentration. There exists a transition of superconductor to non-superconductor with the change of Al doping fraction. The substitution of boron by carbon results in the decrease of the transition temperature since the decrease of the electron concentration and the lattice constant. The theoretical predictions agree with experimental observations.

关 键 词：SUPERCONDUCTIVITY first-principles calculations density of states 

分 类 号：O511[理学—低温物理]