Angle-Resolved Ultraviolet Photoemission Investigation of the Surface Electronic Structures

表面电子结构的角分辨紫外光电发射研究

• 批准号: 63540247
• 负责人: SAKISAKA Yasuo
• 金额: $ 1.15万
• 依托单位: KYOTO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63540247/
• 关键词: Angle-resolved photoemission spectroscopy; Surface electronic states; High-T_c oxide superconductors; Band structure; Fermi liquid; 角度分解紫外光電子分光; 単結晶表面

In order to carry out an angle-resolved ultraviolet photoemission spectroscopy (ARUPS) research into the electronic band structures of clean and gas-adsorbed transition-metal single-crystal surfaces and of single-crystal oxides, we made a computer-controlled data-acquisition system the first thing. After that, we performed ARUPS studies on single-crystal high-T_c oxides, YBa_2Cu_3O_<7-x> (001) and Nd_<2-x>Ce_xCu O_4 (001), and on clean and gas-adsorbed Fe(110) surfaces, and we have obtained the following new results:1. APUPS of epitaxially grown YBa_2Cu_3O_<7-x> (001) single-crystal thin films, exhibiting sharp (1X1) LEED patterns, reveals a clear Fermi edge and fine structures near the edge. Some of the valence-band photoemission features show k-space dispersion. These results suggest that the electronic structure of this oxide can be treated within the framework of the one-electron band picture.2. ARUPS of epitaxially grown Nd_<2-x>Ce_xCuO_4(001) single-crystal thin films, exhibiting sharp (1X1) LEM patterns, reveals a resolution-limited Fermi edge and small k-space dispersion (0.2-0.4 eV) of the valence bands. The ARUPS spectra can be compared to the band calculation to a fair degree. A bandlike state of dominant Cu 3d character is found just below the Fermi level. This state may be a Kondo-type renormalized heavy-electron band.3 . ARUPS of Fe(110) reveals spin-orbit splitting of the upper 3d band into two components separated by -110 meV, being much larger than theoretical estimate (-45 meV).

为了用角分辨紫外光电子能谱（ARUPS）研究清洁和吸附气体的过渡金属单晶表面及单晶氧化物的电子能带结构，我们首先研制了一套计算机控制的数据采集系统。在此基础上，我们对单晶高温氧化物YBa_2Cu_3O_<7-x>（001）和Nd_<2-x>Ce_xCu O_4（001），以及清洁的和气体吸附的Fe（110）表面进行了ARUPS研究，得到了以下新的结果：1.外延生长的YBa_2Cu_3O_<7-x>（001）单晶薄膜的APUPS显示出清晰的（1X 1）LEED图，显示出清晰的费米边缘和边缘附近的精细结构。一些价带光电发射特征显示出k-空间色散。这些结果表明，这种氧化物的电子结构可以在单电子能带图的框架内处理.外延生长的Nd_<2-x>Ce_xCuO_4（001）单晶薄膜的ARUPS显示出清晰的（1X 1）LEM图案，显示出有限的费米边和小的k空间色散（0.2-0.4 eV）。ARUPS光谱可以在相当程度上与频带计算进行比较。一个带状状态的主导铜3d字符被发现低于费米能级。这个态可能是近藤型重正化电子带. Fe（110）的ARUPS揭示了上3d带的自旋-轨道分裂为两个分开约110 meV的分量，远大于理论估计值（约45 meV）。

项目成果

Y.Sakisaka: "AngleーResolved Photoemission Investigation of the Electronic Band Properties of YBa_2Cu_3O_<7-x>(001)" Phys.Rev.B. 39. 9080-9090 (1989)

Y.Sakisaka：“YBa_2Cu_3O_<7-x>(001) 电子带特性的角分辨光电研究”Phys.Rev.B. 39. 9080-9090 (1989)

Y.Sakisaka: "Angle-Resolved Photoemission Study of Relativistic Effects in the Bulk Electronic Structure of Fe" Physical Review B.

Y.Sakisaka：“Fe 体电子结构中相对论效应的角分辨光电研究”物理评论 B。

Y.Sakisaka: "AngleーResolved Photoemission from Nd_<2-x>Ce_xCuO_4(001):A dispersive band like Fermiーliquid state of Cu3d Character near the Fermi level" Phys.Rev.B.

Y.Sakisaka：“来自 Nd_<2-x>Ce_xCuO_4(001) 的角分辨光发射：费米能级附近 Cu3d 特性的像费米液态的色散带”Phys.Rev.B。

Y.Sakisaka: "Comment on “High-Resolution Photoemission Study of the Low-Energy Excitations Reflecting the Superconducting State of Bi-Sr-Ca-Cu-O Single Crystals"" Physical Review Letters. 63. 2315 (1989)

Y.Sakisaka：“对反映 Bi-Sr-Ca-Cu-O 单晶超导状态的低能激发的高分辨率光电发射研究的评论”《物理评论快报》63. 2315 (1989)

Y.Sakisaka: "AngleーResolved Photoemission from Epitaxial Nd_<2-x>Ce_xCuO_4(001)Films" Solid State Commun.

Y.Sakisaka：“外延 Nd_<2-x>Ce_xCuO_4(001) 薄膜的角分辨光电发射”固态通讯。