讲座题目： E-field Control of Magnetism in Layered Multiferroic Heterostructures and Devices, a New Paradigm for Tunable RF/Microwave Components and Spintronics

报告人：Prof. Nian X. Sun

时 间：8月18日（周四）下午3：00
地 点：方正301会议室
主持人：董蜀湘教授    

报告内容摘要：
    Electrical field control of magnetism has been attracting a great amount of recent interest due to its potential technological impacts. The coexistence of electrical polarization and magnetization in multiferroic materials provides great opportunities for realizing effective electric field control, or vice versa, through a strain mediated magnetoelectric interaction effect in layered magnetic/ferroelectric multiferroic heterostructures. Strong magnetoelectric coupling has been the enabling factor for different multiferroic devices, which however has been hard to achieve, particularly at RF/microwave frequencies.In this presentation, we will cover the most recent progress on novel layered microwave multiferroic heterostructures and devices. We will demonstrate strong magnetoelectric coupling in novel microwave multiferroic heterostructures. These multiferroic heterostructures exhibit a giant electrostatically tunable magnetic field of >3000 Oe, and a record high electrostatically tunable ferromagnetic resonance frequency range between 1.75~ 7.57 GHz, a tunable frequency of 5.82 GHz or fmax/fmin=4.3. At the same time, we will demonstrate E-field modulation of exchange bias and realization of electric field controlled near 180° dynamic magnetization switching at room temperature in antiferromagnetic/ferromagnetic/ferroelectric multiferroic heterostructures. Through competition between the E-field induced uniaxial anisotropy and unidirectional anisotropy, large E-field induced tunable exchange field and near 180° deterministic magnetization switching will be demonstrated in exchange coupled multiferroic heterostructures. New multiferroic devices will be covered, which include electric field tunable RF inductors, tunable filters, tunable inductors, phase shifters, miniaturized antennas, etc.

报告人简介：
     Nian Sun is an associate professor at the Electrical and Computer Engineering Department, Northeastern University. He received his Ph.D. degree from Stanford University in 2002. 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, ONR Young Investigator Award, USAF Summer Faculty Fellowship, and the first prize IDEMA Fellowship. His research interests include novel magnetic, ferroelectric and multiferroic materials, devices and subsystems. He has over 80 publications and has >20 patents and patent disclosures. One of his papers published in 2009 was selected as the “ten most outstanding papers in the past decade (2001~2010) in Advanced Functional Materials”.