氧含量对YBa_2Cu_3O_(7-δ)能级结构的影响  

Effect of Oxygen Content on the Energy Level of YBa_2Cu_3O_(7-δ) Superconductors

作　　者：张黄莉[1] 耿兴国[1] 李金山[1] 苏克和[1] 胡锐[1] 张翠萍[2] 文振翼[3] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072 [2]西北有色金属研究院,陕西西安710016 [3]西北大学,陕西西安710068

出　　处：《稀有金属材料与工程》2006年第6期910-912,共3页Rare Metal Materials and Engineering

基　　金：国家自然科学基金重点项目(50432050);陕西省自然基金资助项目(2002B25)

摘　　要：用Gaussian-03软件中的密度泛函理论(DFT)BLYP/LanL2MB方法系统计算了YBa2Cu3O7-δ(0≤δ≤1)不同氧含量时的能级结构,特别是费米面附近的能级特征。根据计算结果发现氧含量对YBa2Cu3O7-δ深层能级影响较小,对最高占据态附近的能级影响较大,且随着氧含量的增加,最高占据态能级降低。计算结果能很好地解释Tc随氧含量变化的实验规律,从一个侧面说明了氧含量在YBCO超导体中的作用机理。Electronic structures were calculated for a series of YBa2Cu3O7-δ （0≤δ≤ 1） in different oxygen concentrations by the density function theory （DFT） at BLYP/LanL2MB level by using Gaussian-03 packages. Attentions have been paid especially to the energy level feature near the Fermi level. The results show that the oxygen concentration would greatly influence the energy levels around the highest occupied orbital, but the inner energy levels a little. When the oxygen concentration increases, the energy level of the highest occupied orbit decreases and the state density increases. This is consistent with the experimental observation of Tc values at different oxygen concentrstions.

关 键 词：YBA2CU3O7-Δ 能级结构 氧含量 

分 类 号：TG113[金属学及工艺—物理冶金]