| 铁电体SrBi2Nb2O2电子能带结构的第一性原理研究 |
| |
| 引用本文： | 唐春红,蔡孟秋,尹真,张明生. 铁电体SrBi2Nb2O2电子能带结构的第一性原理研究[J]. 物理学报, 2004, 53(9): 2931-2936 |
| |
| 作者姓名： | 唐春红 蔡孟秋 尹真 张明生 |
| |
| 作者单位： | (1)南京大学物理系，固体微结构实验室，材料分析中心，南京 210093; (2)南京大学物理系，固体微结构实验室，材料分析中心，南京 210093;南京工程学院基础部，南京 210013 |
| |
| 基金项目： | 国家自然科学基金(批准号:10174034, 10374047)和江苏省自然科学基金(批准号:BK2001026)资助的课题. |
| |
| 摘 要： | 采用第一性原理的方法计算了SrBi2Nb2O.9（SBN）的顺电相、铁电相的电子结构.顺电相是间接带隙, 铁电相是直接带隙，它们的大小分别为1.57和2.23 eV.顺电相和铁电相的价带顶均主要来自于O2p态的贡献.而顺电相和铁电相的导带底则分别来自Nb4d态和Bi6p态的贡献.计算表明SBN铁电相的低的漏电流与Bi 6p轨道有关.由顺电相到铁电相时，Nb4d和O2关键词：顺电相铁电相态密度电子能带结构
|
| 关 键 词： | 顺电相 铁电相 态密度 电子能带结构 |
| 文章编号： | 1000-3290/2004/53(09)/2931-06 |
| 收稿时间： | 2003-11-13 |
Electronic band structure of ferroelectric SrBi2Nb2O9 |
| |
| Tang Chun-Hong,Cai Meng-Qiu,Yin Zhen and Zhang Ming-Sheng. Electronic band structure of ferroelectric SrBi2Nb2O9[J]. Acta Physica Sinica, 2004, 53(9): 2931-2936 |
| |
| Authors: | Tang Chun-Hong Cai Meng-Qiu Yin Zhen Zhang Ming-Sheng |
| |
| Abstract: | The electronic band structures of SrBi 2Nb 2O 9 (SBN) in both the ferroelectric and paraelectric phases were calculated using first principles method. The paraelectric phase is of an indirect band gap of 1 57eV ; whereas the ferroelectric phase is of a direct band gap of 2 23eV. The valence band maxima of both the paraelectric and ferroelectric phases are mainly contributed from O2p states; while the conduction band minima are from Nb 4d and Bi 6p states. When transforming from the paraelectric to the ferroelectric phases, the strong hybridization between Nb 4d and O 2p and Bi O(2) hybridization enhance the distortion of NbO 6 octahedra and reduce the total energy of the system,in favor of stabilizing the ferroelectric phase. The calculation shows that the low leak current in SBN is related to Bi 6p state. |
| |
| Keywords: | paraelectric ferroelectric density of states electronic band structure |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《物理学报》浏览原始摘要信息 |
|
点击此处可从《物理学报》下载免费的PDF全文 |
