题目：Quasicrystals: Stability, Structures and Surfaces

（准晶的稳定性，结构和表面）

报告人：蔡安邦教授

语言：中文

地点：3号楼401会议室

时间：2016年11月4日（周五）下午1：30-2：30

蔡安邦教授介绍

A.P. Tsai（蔡安邦）是日本东北大学（Tohuku University）的Distinguished Professor。1990年在东北大学获得博士学位后留校工作，1996年加入日本国立物质材料科学研究所（NIMS），2004年回到东北大学任全职教授，2015年成为东北大学Distinguished Professor，同时是筑波大学、名古屋大学、法国科学院的客座教授。蔡教授是准晶、非晶、催化领域的专家，在包括Nature, Nature Materials, PRL等高水平期刊上发表论文400篇，引用次数11000余次，H因子56。

摘要

Quasicrystals: Stability, Structures and Surfaces

A.P. Tsai

Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan

Quasicrystal (Qc) is no longer a unique structure matter since it has been confirmed as an equilibrium phase in more than one hundred alloys [1]. It is clear that stability of stable Qcs can be understood within the framework of Hume-Rothery rules. Interestingly, it is found that stable Qcs are even more strict electron compounds, which only formed for alloys with sharp valence electron concentration (e/a: electron-atom ratio). Actually, most stable Qcs were discovered on the basis of the e/a criterion. With these stable Qcs, structure analysis is allowed to study on a single grained sample. Although few structure models have been proposed, they still suffered from considerable uncertainty due to topological and chemical disorder. Recently, understanding in structure has been highly improved in a binary Cd-Yb Qc. Furthermore, observed surface structures of quasicrystals by STM have been well interpreted by bulk structural model. This talk will mainly deal with three topics; the first one is the Hume-Rothery rules for stable Qcs, the second one is regarding the structure of a binary Cd-Yb Qc [2] and the last is the surface structures in relation to bulk structural models for Qcs. Interesting physical properties reported very recently will be introduced.

[1] Chem. Soc. Rev. 42(2013) 5352.

[2] Nature Materials, 6(2007)58.

欢迎老师和同学们参加。