STUDY OF SURFACE PHASE TRANSITION BY HIGH-RESOLUTION

高分辨率表面相变研究

• 批准号: 11650027
• 负责人: NAGAO Tadaaki
• 金额: $ 2.37万
• 依托单位: UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650027/
• 关键词: HREELS; DIFFRACTION; PHONON; PLASMON; ELECTRON; PHASE TRANSITION; EEENERGY DISPERSION; MBE; シリコン; 回子回析; 表面; 電子エネルギー損失分光

Angle-resolved high-resolution electron energy loss spectroscopy (HREELS) has been widely applied for the study of energy dispersion curves of surface phonons and surface plasmons. However, wide acceptance angles and the limited angular scanning in a 1 dimensional manner in conventional high-resolution electron energy loss spectrometers has been hindering the detailed studies of phonon anomalies during phase transitions as well as low-dimensional plasmon modes (sheet plasmons, wire plasmons). Also, in situ studies of surface phase transitions during temperature change or during molecular beam epitaxy (MBE) are difficult using the electron beams of conventional HREELS.Here in this project, we have developed a new version of an electron energy loss spectrometer which is capable of measuring high-resolution EELspectra as well as high-resolution diffraction by use of monochromatised slow electron beams during MBE and sample heating [reference 1]. Comprehensive study of phase transition will be performed by correlating possible phonon anomalies with the spot profile/intensity analyses of the diffraction patterns. Also, energy dispersion curves of low-dimensional plasmon modes, which are impossible to measure with conventional spectrometers, can be studied by utilizing its high momentum resolution [reference 2].

角分辨高分辨率电子能量损失谱（HREELS）已广泛应用于表面声子和表面等离子体的能量色散曲线研究。然而，传统的高分辨率电子能量损失光谱仪的宽接受角和有限的一维角度扫描阻碍了对相变过程中的声子异常以及低维等离子体模式（片等离子体、线等离子体）的详细研究。此外，在温度变化或分子束外延（MBE）过程中，使用传统的hrel电子束很难在原位研究表面相变。在这个项目中，我们开发了一种新版本的电子能量损失光谱仪，它能够在MBE和样品加热过程中使用单色慢电子束测量高分辨率eel谱和高分辨率衍射[文献1]。通过将可能的声子异常与衍射图的斑点分布/强度分析相关联，将对相变进行全面的研究。此外，利用其高动量分辨率可以研究传统光谱仪无法测量的低维等离子体模式的能量色散曲线[文献2]。

项目成果

Tadaaki NAGAO: "Obscrration of two-dimensional plasmon in a metallic monolayer on silicon surface"Proceedings of 25^<th> International Confernce on the Physics of Semiconductors. (in press). (2001)

Tadaaki NAGAO：“硅表面金属单层中二维等离子体激元的观测”第 25 届国际半导体物理会议论文集。

Tadaaki NAGAO: "Observation of two-dimensional plasmon in a metallic monolayer on silicon surface"Proceedings of 25th International Conference on the Physics of Semiconductors. 印刷中. (2001)

Tadaaki NAGAO：“硅表面金属单层中的二维等离子体激元的观察”第 25 届国际半导体物理会议论文集（2001 年）。

Takekaru Sekiguchi: "A series of Ca-induced reconstructions on Si(111) surface"Surface Science. (2001)

Takekaru Sekiguchi：“Si(111) 表面上的一系列 Ca 诱导重建”表面科学。

Tadaaki NAGAO: "Obscrration of two-dimensional plasmon in a metallic monolayer on silicon surface"Proceedings of 25^<th>International Confernce on the Physics of Semiconductors. (印刷中). (2001)

Tadaaki NAGAO：“硅表面金属单层中的二维等离子体激元的观测”第 25 届国际半导体物理会议论文集（2001 年）。

Tadaaki NAGAO: "Two-dimensional plasmon in a surface-state band"Surface Science. (印刷中). (2001)

Tadaaki NAGAO：“表面态带中的二维等离子体”表面科学（2001 年）。