Prof. Can Cui [Zhejiang Science & Technology University]

Title: Tsai-type quansicrystals

Time: 14:00 - 15:00, September 10
Place: Auditorium Room 410, Bldg 6, HPSTAR (Shanghai)
Host: Wenge Yang

Abstract:
Quasicrystal (QC) differs from conventional crystalline and amorphous materials in exhibiting long-range order with crystallographically forbidden symmetries, such as 5-, 8-, 10- and 12-fold rotational symmetries. The 2011 Nobel Prize in Chemistry was awarded to Dan Shechtman for the discovery of QCs, considerably raising awareness of QCs in the field of science and technology. They were first discovered in Al-Mn alloys and have since been found in numerous metallic alloys. More recently, QCs are even being found in self-assembled colloidal/molecular systems, polymers and perovskite oxide thin films. It is now clear that quasiperiodicity is universal in thermodynamic equilibrium states of matters. Most of the metallic QCs synthesized so far are in the icosahedral phase. Icosahedral QCs (i-QCs) can be classified into three types: the Mackay (Al-Mn-Si) type, the Bergman (Zn-Mg-Al) type and the Tsai (Cd-Yb) type, as defined by the structures of the icosahedral multi-shell clusters that are the major building units of i-QCs. The Tsai-type QC was named after their discoverer, An Pang Tsai, who identified the first stable binary QC, i-Cd5.7Yb, in 2000. This discovery triggered subsequent discoveries of a variety of Tsai-type QCs in various alloy systems. Today, they form the largest QC family of the three types. In this report, I will present the recent studies on Tsai-type quasicrystal, including the atomic structure, the crystal growth of single-grain, the physical properties and the surface studies.

Biography of the speaker:
Dr. Can Cui is a professor and also the dean of the Department of Physics, Zhejiang Sci-Tech University. He received his BSc and PhD from Zhejiang University in 2001 and 2006. He worked as a postdoctor in Prof. An Pang Tsai’s group (Tohoku University, Japan) from 2007 to 2009. His current research activity concerns the quasicrystals and the optoelectronics materials.