报告题目：氧化物和碳结构新奇材料设计 Novel Material with novel properties
报 告 人：Swarnakamal Mukherjee Satyendra Nath Bose National Centre for Basic Sciences, India
报告时间：2016年5月5日(周四)上午10:00PM
报告地点：校本部E106会议室，8455新葡萄场网站量子与分子结构国际中心SHU ICQMS
邀 请 人：任伟教授
报告摘要：
Scientists in this recent time are investing a lot of effort to study the physical and chemical properties of the materials. For advancement of industry, material science engineering has become a hot research topic in both theoretical and experimental fields. The vast variety of structural and physical properties exhibited by materials makes them promising for industrial applications. In this context I would like to highlight two distinct types of materials with novel properties:
(1) CaCu3B4O12: Employing first-principles density functional theory based calculations I would like to report the change in electronic structure of CaCu3B4O12 compounds as one moves from 3d (Cr, Co) to 4d (Rh) to 5d (Ir) element at B site. The results show that when descending from Cr/Co to Ir, the charge transfers from the cuprate-like Zhang-Rice state on Cu to the t2g orbital of the B site. As the Cu d-orbital occupation approaches the Cu2+ limit, a mixed valence state in CaCu3Rh4O12 and heavy fermion state in CaCu3Ir4O12 are noticed. The investigated d-electron compounds are mapped onto the Doniach phase diagram of the competing RKKY and Kondo interactions developed for the f-electron systems.
(2) C60: Stone-Wales (SW) transformation is a key mechanism responsible for the growth, transformation, and fusion in fullerenes, carbon nanotubes, and other carbon nanostructures. These topological defects also substantially alter the physical and chemical properties of the carbon nanostructures. However, this transformation is thermodynamically limited by very high activation energy (∼7 eV in fullerenes). Using first-principles density functional calculations, I would like to report that the substitutional boron doping substantially reduces the SW activation barrier (from ∼7 to 2.54 eV). Analysis of bonding charge density and phonon frequencies suggests that the bond weakening at and around the active SW site in B heterofullerenes is responsible for such a reduction.
Short bio: I have recently submitted my Ph. D. thesis on computational material science entitled as "Electronic Structure Of Crystalline Solids And Finite-Sized Clusters" at the University of Calcutta. My Ph. D. programme at the University of Calcutta has been conducted through Satyendra Nath Bose National Centre for Basic Sciences (Block-JD, Sector-III, Salt Lake, Kolkata-700 106). My basic interest is in polar-magnetic oxides and low-dimensional structural composite. All my first-principle based calculations are performed mainly by using VASP, WIEN2k like standard DFT packages. I finished my M. Sc. (Physics) from Visva-Bharati University in 2008.
