报告人：钟虓䶮 香港城市大学材料科学与工程副教授
报告地址：华南农业大学2号楼人工智能与低空技术学院207会议室
报告简介：
磁性氧化物材料被广泛应用于国民经济和国家安全中的各个领域，信息科技的高速发展尤其对磁性氧化物材料的先进性能研发提出了迫切需求。实现自旋构型与材料结构的原子尺度协同定量表征，是理解、预测与调控磁性材料的物理性能的关键。
近年来，随着电子磁圆二色性谱（Electron Magnetic Circular Dichroism, EMCD）,也称电子能量损失磁手性二向色性谱（Electron Energy-loss Magnetic Chiral Dichroism）的出现，电子显微学在微观磁结构与磁性能研究领域有了突破性的进展。通过EMCD可获得材料的本征磁圆二色性（Magnetic Circular Dichroism, MCD）谱，进而定量计算得到材料中不同元素各自的总磁矩、轨道磁矩、自旋磁矩等磁学信息。近期我们通过色差校正的透射电子显微镜实现了原子面分辨的磁圆二色谱成像技术，结合先进的像差校正透射电子显微镜的结构和化学成像技术，可以从同一样品区域在原子尺度同时获得材料的自旋构型，原子排布，化学信息等，为原子尺度了解磁性材料的构效关系奠定了基础。此外，我们利用纳米束EMCD技术，结合球差校正电镜和第一性原理计算对尖晶石铁氧体中以盐岩结构作为中间层的新型反相畴界处的原子构型、磁性起源进行了表征，实现了原子尺度缺陷结构-成分-磁性协同测量。该项原子尺度结构-成分-磁矩协同表征技术，推进了对先进磁性材料的表征与调控。
报告人简介：
Dr. Xiaoyan Zhong is currently an associate Professor in the Department of Materials Science and Engineering at City University of Hong Kong. He received his B.S. degree in 2001 and PhD degree in 2007 in Materials Science and Engineering at Tsinghua University. After three-year postdoctoral research at Argonne National Laboratory in USA, he began his independent academic career at Tsinghua University from 2010 to 2020. He joined City University of Hong Kong since May 2020. His current research interests involve methodology development of transmission electron microscopy and spectroscopy and their application in solving new challenges in magnetic materials. Recently Zhong's group has developed the quantitative atomic-plane resolved electron magnetic circular dichroism method and pushed spatial resolution of magnetic circular dichroism into atomic level by achromatic electron microscopy, which was published in the peer-reviewed journals such as Nature Materials, Nature Communications and Advanced Functional Materials. He received “Ten Major Scientific and Technological Progress of China's Colleges and Universities” awarded by Ministry of Education of the People’s Republic of China and the Excellent Young Scholar awarded by Chinese Electron Microscopy Society.
