Microscopic Study on the Surface Magnetism by Ultra-slow Muon

超慢μ介子表面磁性的显微研究

基本信息

批准号：
63540242
负责人：
TORIKAI Eiko
金额：
$ 1.28万
依托单位：
YAMANASHI 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-63540242/
关键词：
SURFACE MAGNETISM PARTICLE BEAM MUON SPIN ROTATION

项目摘要

In the beginning of 1989, the government approved a plan to construct a new ultra-slow muon channel in Meson Science Laboratory, University of Tokyo proposed by K. Nagamine, a investigator of the present research project. The new channel is expected to produce high-intensity ultra-slow beam in 1991 with several orders of the magnitude higher than that produced by the conventional facility and will be powerful tool to study the surface magnetism. Considering the future possibilities of the research project, we changed the re- search plan of the final year to concentrate on the development of the high-intensity beam instead to complete the study by using the low intensity beam.The primary results of the research project are summarized as follows; 1. Development of the High-intensity Ultra-slow Muon Beam (i) The concept and the basic design of the new channel of ultra- slow muon is decided based on the laser-excitation method of the thermal muonium. (ii)Thermal muonium emission from thin SiO_2 layer on a Si(100) wafer into vacuum is observed. The SiO_2 thickness dependence of the yield, which becomes maximum at 3 nm, gives the important in formation about the mechanism of the thermal muonium emission. 2. Magnetism of the Magnetic Monolayers with Multilayered Structure by Muon Spin Relaxation (i) The uSR signal of 2% of Oxygen monolayers adsorbed on Graphite is detected from a huge background of Graphite and it gives the evidence for the magnetic phase transition of 2-D antiferromagnet at 12K. (ii) On artificial metallic superlattice MnSb, the signal/background ratio has been carefully estimated to be more than 20% by the preliminary experiment. The result encourages to perform detail experiments on the subject.

1989年初，政府批准了本研究项目研究员K. Nagamine提出的在东京大学介子科学实验室建设新的超慢μ子通道的计划。新通道预计将在1991年产生高强度超慢光束，其数量级比传统设施高出几个数量级，并将成为研究表面磁性的有力工具。考虑到该研究项目未来的可能性，我们改变了最后一年的研究计划，集中精力开发高强度光束，改为利用低强度光束完成研究。该研究项目的主要成果总结如下； 1.高强度超慢μ子束的研制 (i)基于热μ子激光激发方法，确定了超慢μ子新通道的概念和基本设计。 (ii)观察到Si(100)晶片上的薄SiO_2层向真空中的热锷发射。 SiO_2 厚度对产率的依赖性在 3 nm 处达到最大值，这对于热锷发射机制的形成具有重要意义。 2. Mu子自旋弛豫多层结构磁性单层的磁性 (i) 从石墨的巨大背景中检测到吸附在石墨上的2%的氧单层的uSR信号，它为2-磁性相变提供了证据D 反铁磁体，12K。 (ii) 在人造金属超晶格MnSb上，通过初步实验仔细估计信号/背景比超过20%。结果鼓励对该主题进行详细的实验。