Abstract：

Due to the upcoming demands of the next-generation electronic devices with low energy consumption, high storage density and high write-read speed, emerging correlated materials and structures  are highly desired. Recently, especially for the last decades, multiferroics attract people’s interests due to their relatively high transition temperature and being chemically robust at ambient atmosphere. Among the natural and artificial compounds, BiFeO3 (BFO) is one of the most promising materials due to its high ferroelectric and antiferromagnetic transition temperature. In this talk, I will firstly give an introduction about crystal, polar and spin structures of BFO, and how the spin and polar can couple each other in its ground state and highly strained states. Based on this understanding, I will talk about the strong magnetoelectric coupling in BFO-related systems at reduced dimensions (e.g. heterointerface, domain walls, and phase boundary etc.). Taking advantage of this multiferroic model system, we are able to have opportunities to better understand the emerging coupling in other ferroic materials. In the last part of my talk, I will briefly introduce a low-energy-cost strategy to deterministically drive a single magnetic-domain-wall motion by a nanoscale probe-induced spin displacement. These reversible controls of the electric, magnetic and elastic order parameters demonstrate possible applications in future electronic and magnetoelectronic devices.  

报告人简介：

张金星，博士，研究员。2009 年12 月毕业于香港理工大学应用物理系并获理学博士学位，其中2008 年8 月到2009 年11 月在加州大学伯克利分校材料系访问研究并在伯克利完成博士论文。博士毕业后留在加州大学物理系从事博士后研究（合作导师R.Ramesh教授）。2012年被北京师范大学以海外高层次人才引进，目前为北京师范大学物理系研究员。2013年9月获得国家自然基金委优秀青年基金。

张金星的主要研究方向是过渡金属氧化物薄膜的外延生长，关联体系尤其纳米尺度下表面界面处新奇特性的探测与调控，及其在信息技术、能源转化、传感驱动等方面的应用。