报告题目：Electronic strain and chemical doping for improvement of materials performance properties

报告人： Prof. Shi Xue Dou (窦士学 教授 博导)

澳大利亚技术科学与工程院院士、Wollongong大学超导与电子材料研究所所长

报告时间：9月30日(周一) 上午9:30

报告地点：北京航空航天大学 为民楼743室

报告摘要： In this talk, I will show the significant role of strain engineering in materials design and formulation. Carbon-based dopants have been widely used for modification of materials properties. In MgB₂ superconductors, Carbon including malic acid, SiC & amorphous C is the most powerful dopant that has dramatically improved critical current density and upper critical field. The role of C doping in MgB2 is to induce local inhomogeneity that results in electronic strain at nano scale. For newly discovered Fe based superconductors, potassium (K) doping in BaFe₂As₂ (122) induces superconductivity and its large variations in distribution enable the coexistence of AFM and SC phases at lattice scale, leading to localised electronic inhomogeneity. Both K doping in 122 and C doping MgB₂ share the common feature that is the doping induces electronic strain which is responsible for flux pinning and increased H_c2. In energy materials area, ZnO is a promising high figure-of-merit (ZT) thermoelectric material for power harvesting from heat due to its high melting point, high electrical conductivity σ, and Seebeck coefficient α, but its practical use is limited by a high lattice thermal conductivity. We use Al-doping to induce electronic strain and hence enhanced phonon scattering, resulting in reduction of thermal conductivity and high-ZT oxide-based thermoelectrics for applications at high temperatures. For Li ion battery, the huge volume change during cycling caused crumble in electrodes in Li-ion battery. By forming a composite or carbon encapsulation or dimensionality change or fabrication of nanoscale materials, the modified electrodes can not only achieve high capacity but also retain long cycle life as the carbon network remains well intact although individual grain may be cracked.  Strain engineering has a great potential for materials design and formulation at both structural and electronic levels.  Next generation high energy and high power density storage system may consist of strain-controlled silicon anode, chemical doped high voltage cathode and hybrid liquid ionic electrolytes.

报告人简介：Shi Xue Dou is Professor and Director of the Institute for Superconducting and Electronic Materials (ISEM) at UOW. He received his PhD in chemistry in 1984 at Dalhousie University, Canada. He was elected as a Fellow of the Australian Academy of Technological Scienceand Engineering in 1994. He was awarded a DSc by theUniversityofNew South Walesin 1998 and three Australian Professorial Fellowship by Australian Research Council in 1993, 2002 and 2007. He received the Australian Government’s Centenary Medal in 2003, Vice-Chancellors Senior Excellence Award in 2008, Vice-Chancellor Outstanding Partnership Award in 2012. He is author and co-author of more than 600 refereed journal papers, attracting over 14000 citations with a h-index >53. He has given 100+ invited talks at international conferences and institutions around the world. He has led more than 50 ARC and other competitive projects as a lead chief investigator. Dou is specialized in energy and superconductor materials including high performance superconductor wires for applications such as MRI, electrical devices, and energy storage materials for electric vehicles. He is program leader for ongoing Automotive CRC 2020. He has supervised 65 PhD students and more than 50 postdoctoral and visiting fellows who are widely spread across five continents, working within the fields of science, technology, and industry. They have made significant contributions in their fields and established themselves as research leaders on their own right.