Development of field-emission low-energy electron diffraction apparatus for complex surface structures

2017 Fiscal Year Final Research Report

• Project/Area Number: 15H03677
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Condensed matter physics I
• Research Institution: Kyushu University
• Principal Investigator: Mizuno Seigi 九州大学, 総合理工学研究院, 教授 (60229705)
• Co-Investigator(Kenkyū-buntansha): 柚原 淳司 名古屋大学, 工学研究科, 准教授 (10273294) ; 中川 剛志 九州大学, 総合理工学研究院, 准教授 (80353431)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 表面構造解析 / 低速電子回折 / 電界放出電子線 / 電界誘起ガスエッチング / ２次元超薄膜

Outline of Final Research Achievements

Low-energy electron diffraction apparatus using field emission gun has been developed. The electron beams were emitted from tungsten tips those were sharpened by chemical electro-polish and field-assisted gas etching. The field-assisted gas etching was done in the ultra-high vacuum chamber using oxygen, nitrogen and water vapor, and the tip apexes were atomically sharpened. These tip apexes could emit electron beams at low energies with small opening angles, and the beams were focused on the sample surfaces using magnetic lenses. The diffracted electron beams were measured by microchannel plate. The spot sizes of obtained diffraction patterns were smaller (40%) than those of the conventional apparatus. The origin of sharpness of the developed apparatus is high coherence length of the field emission beams. It demonstrates that the new apparatus opens up a way to analyze very complex surface structures.

Free Research Field

表面科学