CHANGE OF ELECTRONIC STRUCTURES CAUSED BY LOCAL SUBSTITUTION OF Zn FOR Cu IN YBa2Cu3O7 MATERIAL
Zn局域替代YBa2Cu3O7中的Cu引起的电子结构变化

Using Recursion method, we have studied the change of electronic structures caused by local substitution of Zn for Cu(2) in YBa2Cu3O7 material. It is found that the substitution has important effect on the properties of the substituted site and its neighbours, which include the partial wave densities of states, the type and strength of bonds, and the atomic valence of sites. On the basis of calculations, we analyze the mo ement of charge and believe that the decrease of hole concentration in CuO2 layers is the dominant factor in lowering the superconducting transition temperature of YBa2Cu3O7 when Zn substitutes Cu in small amounts.