物理化学学报 >> 2009, Vol. 25 >> Issue (01): 61-66.doi: 10.3866/PKU.WHXB20090111

研究论文 上一篇    下一篇

PbxSr1-xTiO3的电子结构

张富春; 张志勇; 张威虎; 阎军峰; 江妮   

  1. 中国科学院西安光学精密机械研究所, 西安 710068; 延安大学物理与电子信息学院, 陕西 延安 716000; 西北大学信息科学与技术学院, 西安 710127
  • 收稿日期:2008-06-30 修回日期:2008-09-01 发布日期:2008-12-31
  • 通讯作者: 张志勇 E-mail:zhangzy@nwu.edu.cn

Electronic Structure of PbxSr1-xTiO3

ZHANG Fu-Chun; ZHANG Zhi-Yong; ZHANG Wei-Hu; YAN Jun-Feng; YUN Jiang-Ni   

  1. Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an 710068, P. R. China; College of Physics & Electronic Information, Yan’an University, Yan’an 716000, Shaanxi Province, P. R. China; School of Information Science and Technology, Northwest University, Xi’an 710127, P. R. China
  • Received:2008-06-30 Revised:2008-09-01 Published:2008-12-31
  • Contact: ZHANG Zhi-Yong E-mail:zhangzy@nwu.edu.cn

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摘要： 在广义梯度近似下, 采用基于密度泛函理论框架下的超软赝势平面波和虚拟晶体近似方法, 计算了不同Pb/Sr摩尔比的PbxSr1-xTiO3(PST)固溶体的精细结构, 确定了A位离子在铁电相的平衡构型. 利用虚拟晶体近似方法分别计算了摩尔比x为0.6、0.7的PbxSr1-xTiO3精细结构. 结果表明, 在钛酸锶铅固溶体中, 随着Pb的摩尔比增大, 晶胞体积膨胀, c/a值增大. 当0.6

关键词: 钛酸锶铅, 铁电性, 密度泛函理论, 虚拟晶体近似

Abstract: Fine structures for PbxSr1-xTiO3 (PST) solid solutions with different mole ratios of Pb/Sr were calculated by adopting the plane wave ultra-soft pseudo-potential and virtual crystal approximation technology based on density functional theory (DFT) within the generalized gradient approximation. The equilibrium configuration of A-site cations (Pb and Sr) in the ferroelectric phase was determined. The fine structures for PbxSr1-xTiO3 were studied by using the virtual crystal approximation for mol ratios (x) of 0.6 and 0.7. The calculations reveal that the cell volume expands and the c/a ratio increases with an increase of Pb content. These results further indicate that the composition range of the cubic to tetragonal phase boundary is about 0.6

Key words: (Pb,Sr)TiO3, Ferroeletronic, Density functional theory, Virtual crystal approximate