报告题目Title：Structural and Electronic Transitions in Heavy Metal Oxides. Systems containing Technetium or Uranium.( 重金属氧化物的结构和电子相变)
报 告 人Speaker：Prof. Brendan J. Kennedy(悉尼大学)
报告时间Time：2016年9月29日(周四) 10:00
报告地点Venue：校本部E106会议室（永利量子与分子结构国际中心SHU ICQMS）摘要：Establishing structure-property relationships is often the key to the rational design of new functional materials. The 4d metal oxides are gaining considerable attention in the search for materials with novel properties as a consequence of their tendency to exhibit wide electronic bands, reflecting the broad, spatially extended nature of 4 d electronic wave functions, with relatively weak electronic correlations, strong crystal field effects and spin-orbit coupling. A feature of many oxides utilised in devices is that they are poised near an instability, such that small changes in environment, temperature or pressure, can result in a structural or electronic phase transition. Understanding the phase transition behaviour can be key to discerning the structure-property relationship and ultimately guide the discovery of new materials.
Working with the heavier metal oxides presents experimental challenges, associated with their toxicity and radioactivity, both for their synthesis and subsequent characterisation, especially when the studies are conducted at high temperatures. In this talk I will describe recent results of two ongoing projects at the University of Sydney, namely studies of Tc containing oxides and phase transition behaviour in AUO4 uranates. Neutron scattering plays a critical role in these studies.
1. E. E. Rodriguez, F. Poineau, A. Llobet, B. J. Kennedy, M. Avdeev, G. J. Thorogood, M. L. Carter, R. Seshadri, D. J. Singh and A. K. Cheetham, High-temperature magnetic ordering in the 4d perovskite SrTcO3, Phys. Rev. Lett. 2011 106, 067201.
2. G. Murphy, B.J. Kennedy, J. Kimpton, Q-F Gu, B. Johannessen, et al : Non Stoichiometry in Strontium Uranium Oxide: Understanding the rhombohedral – orthorhombic transition in SrUO4 Inorganic Chemistry In press.
