...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Applied Physics >Investigation of surface defect states in CeO2-y nanocrystals by Scanning−tunneling microscopy/spectroscopy and ellipsometry
【24h】

Investigation of surface defect states in CeO2-y nanocrystals by Scanning−tunneling microscopy/spectroscopy and ellipsometry

机译：CeO 2-y 纳米晶体的表面缺陷状态的扫描隧道显微镜/光谱法和椭偏仪研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Synthesis process strongly influences the nanocrystalline CeO defective structure. The presence of surface defects, in the form of oxygen vacancies in different charge states (F centers), can change the electronic properties of ceria nanocrystals. Nanocrystalline CeO samples were synthesized using three different methods (precipitation, self-propagating room temperature, and hydrothermal synthesis). Raman spectroscopy was used to identify the presence of oxygen vacancies which presumably were formed at the nanoparticle surface. The defect concentration depended on the crystallite size of differently prepared CeO samples. Scanning tunneling microscopy/spectroscopy and ellipsometry were employed to investigate the electronic band structure of defective CeO nanocrystals. Scanning tunneling spectroscopy measurements demonstrated that inside the band gap of CeO nanocrystals, besides the filled 4 f states, appeared additional states which were related to occupied and empty F center defect states. From the ellipsometric measurements, using the critical points model, the energy positions of different F centers states and the values of the reduced band gap energies were determined. The analysis of obtained data pointed out that depending on the synthesis method, different types of F centers (F and F) can be formed in the CeO nanocrystals. The formation of different F center defect states inside the ceria gap have a strong impact on the electrical, optical, and magnetic properties of ceria nanocrystals.
机译：合成过程强烈影响纳米晶CeO缺陷结构。以不同电荷态（F中心）的氧空位形式存在的表面缺陷会改变二氧化铈纳米晶体的电子性能。使用三种不同的方法（沉淀，室温自蔓延和水热合成）合成了纳米CeO样品。拉曼光谱法用于鉴定氧空位的存在，该氧空位可能是在纳米粒子表面形成的。缺陷浓度取决于不同制备的CeO样品的微晶尺寸。扫描隧道显微镜/光谱法和椭偏仪用于研究有缺陷的CeO纳米晶体的电子能带结构。扫描隧道光谱法测量表明，在CeO纳米晶体的带隙内，除了填充的4 f状态外，还出现了与占据和空F中心缺陷状态有关的其他状态。根据椭偏测量，使用临界点模型，确定了不同F中心状态的能量位置以及减小的带隙能量的值。对获得的数据的分析指出，根据合成方法，可以在CeO纳米晶体中形成不同类型的F中心（F和F）。在二氧化铈间隙内形成不同的F中心缺陷态对二氧化铈纳米晶体的电，光和磁性能有很大的影响。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号