报告题目：Experiments on board the ISS with SiGe melts
报告人：Dr. Yuansu LUO (physical Institute, Georg-August-University, Göttingen, Germany)
报告时间：2019年4月17日（周三）下午15：00
报告地点：物理学院新楼五楼多功能厅
报告摘要：
The processing of semiconductors based on electromagnetic levitation (EML) is a challenge, because this kind of materials shows a poor electrical conductivity (σ).
In the framework of an ESA (European Space Agency) project, first attempts with highly doped Si1-xGex were made currently on board the ISS (International Space Station), where the contactless measurements on different kinds of materials were designed in EML under the microgravity condition.
Initial results indicate that although a lower σ compared to metals, the processing of the semiconductors SiGe is successful in EML with a large overheating (>350℃) in melts, which guarantees the homogeneity and thus leads to a large supercooling (~250℃) before the solidification via a homogenous nucleation.
By means of video techniques and a subsequent digital image procedure, we determined thermophysical properties of the samples, including thermal expansion β, viscosity η, surface tension γ as well as the impact from compositions. In addition, a semiconductor-metal transition upon melting was studied thereby using a designed sample coupling electronics (SCE) system.
报告人简介：
Current research areas
i) Thin films of metallic glasses -preparation, structure and applications
ii) Contactless measurements of semiconductor melts on board the Zero-G aircraft and the ISS
Career History
Dec. 1981 Diploma in Physics, Wuhan University, Wuhan/China
1982- 86 Assistant & lecture, Physics department of Wuhan University, China/Wuhan
1987 German language course in Tongji- University, Shanghai
1988- 1992 PhD, institute of metal physics, University Göttingen
1992-94 Research Assistant, SFB 345, University Göttingen
1995-99 Postdoc, Physics institute, University Augsburg
1999-now Research & lecture, I. Physics institute, University Göttingen
邀请人：刘昌 教授
