题目：Novel Microwave Magnetic Thin Films and Their Applications in Multiferroic Composite Materials and Devices
报告人： Nian X. Sun  博士
Center for Microwave Magnetic Materials and Integrated Circuits
Electrical and Computer Engineering Department, Northeastern University
主持人：董蜀湘  教授
时间：6月23日（周一）下午3:30
地点：力学楼434会议室

报告内容摘要：
Multiferroic composite materials are a subgroup of materials having two or more ferroic (ferroelectric, ferro/ferrimagnetic, and ferroelastic) phases, in which strong magnetoelectric (ME) effects have been demonstrated. These multiferroic composites and the ME effects are rich in both fundamental sciences and practical applications, such as electrostatically tunable magnetic microwave devices, ultra-sensitive magnetic field sensors, etc. This talk will be started with a brief overview of the multiferroic materials and devices, which will be followed with our most recent work on novel microwave magnetic thin films and their applications in multiferroic composite materials and devices. First I will report on a novel class of microwave magnetic FeGaB films and their applications in FeGaB/Pb(Zr,Ti)O3 and FeGaB/(1?x) [Pb(Mg1/3Nb2/3)O3] ? x[PbTiO3] (PMN-PT) multiferroic composites. Giant microwave ME coupling was observed in the FeGaB/PMN-PT multiferroic composite, which exhibits a large electrostatically tunable frequency range ?f = 900 MHz and f/f = 58%, and a tunable relative permeability between 350~1000. Next I will report on another class of microwave magnetic films, the spin-spray deposited ferrite films, which were applied in novel magneto(di)electric antenna substrates. We will demonstrate the first ever self-biased magnetic antennas at > 1 GHz, which show significantly enhanced antenna efficiency and bandwidth over non-magnetic antennas, and large radiation frequency tunability.

报告人简介：
Dr. Sun received his Ph.D. degree from Stanford University in 2002. He is assistant professor at the Electrical and Computer Engineering Department, Northeastern University. Prior to joining Northeastern University, he was a research scientist at IBM and Hitachi Global Storage Technologies between 2001~2004. Dr. Sun was the recipient of the NSF CAREER Award in 2008, the ONR Young Investigator Award in 2007, and the 1st Prize IDEMA Fellowship in 2000. His research interests include novel magnetic, ferroelectric and multiferroic microwave materials and devices such as antennas, filters, circulators, etc., and materials and device properties at RF/microwave frequency range. Dr. Sun has over 50 publications in journals such as Nature, Physical Review, Applied Physics Letters, etc. He is currently funded by NSF, ONR, Draper Laboratory, etc.

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联系人：侯仰龙  hou@pku.edu.cn  010-8252-9028
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