Category Archives: Publications

Dr. Wu and collaborators have published a review paper in MRS Bulletin

图. (a-e)薄膜椭圆中多种能量的影响(f-g)利用特定切向的PMN-PT实现的磁畴控制(h)利用两组电极实现双轴应力 我校信息学院吴涛教授与弗吉利亚理工大学John Domann教授、台湾交通大学Tien-Kan Chung教授及加州大学洛杉矶分校(UCLA)的Gregory Carman教授受邀,合作撰写了应变介导磁电耦合效应方面的综述文章。近日,该综述以“Strain-mediated magnetoelectric storage, transmission, and processing: Putting the squeeze on data”为题,在国际知名期刊《MRS BULLETIN》上发表。 磁电效应是一个具有广阔应用前景的研究领域。早在1961年,研究人员就在氧化铬中发现了磁电效应。然而单一材料的磁电效应即便在低温下也只能展现较小的磁电耦合,大大限制了该技术的应用。直到2001年,国外研究人员研制出一种由压电和压磁材料组成的复合叠层结构,该器件在室温下展示出了较高的磁电耦合。这种方式被称为“应变介导磁电耦合”。后续研究则利用这种机制更显著地提高了磁电耦合。应变介导磁电耦合可以通过施加电压来控制微磁场,而叠层的复合磁电耦合又大大提高了磁电耦合。目前,应变介导磁电耦合已成为控制微磁场最有效的方式,在信息存储、传输和处理方面有着巨大的应用潜力。 此外,吴涛教授与合作者发表的综述围绕应变介导磁电耦合这一主题,首先回顾了最初在较大尺寸器件上的研究,以及后续对磁性薄膜、微小尺寸异质结和单畴的控制实验,着重讨论了该技术在尺寸、速度和能耗方面的优势;继而阐述了该技术在信息存储、传输和处理方面的应用,举例介绍了储存器、天线和逻辑单元三种器件;最后,展望了应变介导磁电耦合未来的发展趋势及结合反铁磁性材料的应用可能。 综述还介绍了对磁畴在各种激励下变化过程的建模。其中对于薄膜模型,磁弹性能主要取决于双轴应变,而在011切向的PMN-PT中发现了巨大的各向异性滞后,并且可以产生较大的双轴应力。这意味着只需要两个电极就可以在较大的面积上施加均匀的双轴应力,同时具有稳定的两个状态、很高的转换速度和极低的能耗。该技术的优点可以转化为重要的设备指标,如:能源效率、非波动性、更小的尺寸和更快的速度。如果在存储中,磁电耦合使得纳秒级的切换时间成为可能,并因其极低的能耗,大范围使用将可大幅度减少全球在存储上的能耗。 应变介导磁电耦合技术在过去的17年中飞速发展,研究展现了磁电耦合如何为数据操作任务提供了显著的能效改进,同时比传统技术更快、更小。该技术展现了一种崭新的存储、传输和处理信息的范式转换的途径。 该综述涵盖了吴涛教授与合作者在该方向上的重要工作与研究成果。吴涛教授为第二作者,上海科技大学为第二完成单位。该项研究得到了上海市浦江人才计划和上海科技大学科研启动基金的支持。 论文链接:https://doi.org/10.1557/mrs.2018.260 上科大新闻: http://www.shanghaitech.edu.cn/2018/1120/c1001a36232/page.htm

2 Papers accepted for presentation at IEEE MEMS 2018 Conference

The 2 papers have been accepted for presentation at IEEE MEMS 2018 Conference to be held in Belfast, Northern Ireland, UK on 21-25 January 2018. 1. Tao Wu, Zhenyun Qian, and Matteo Rinaldi, “LOW COST THIN FILM ENCAPSULATION FOR ALN

We present our work in 2017 IEEE SENSORS Conference!

Dr. Tao Wu attended and present work titled “Design and Fabrication of AlN RF MEMS Switch For Near-Zero Power RF Wake-Up Receivers” on 2017 IEEE SENSORS Conference held in Glasgow, Scotland, Oct. 30 – Nov. 1, 2017. We describe an AlN-based

Aluminum Nitride RF MEMS

Aluminum Nitride (AlN) piezoelectric nano-plate NEMS resonant devices that can address some of the most important challenges in the areas of physical, chemical and biological detection and can be simultaneously used to synthesize high-Q reconfigurable and adaptive radio frequency (RF)

Tessellated Silicon-Structures for Monocentric Imagers

Compared with conventional planar optical image sensors, a curved focal plane array can simplify the lens design and improve the field of view. In this paper, we introduce the design and implementation of a segmented, hemispherical, CMOS-compatible silicon image plane

Magnetic Nano-Ring and Single Domain

We have patterned magnetic nano-ring and single domain structures of Ni on (011) PMN-PT substrate, and used MFM and X-PEEM technique to characterize the magnetic domain movement in patterned Ni nanostructures. We have achieved a permanent 90° rotation in the

Giant Tunable Piezoelectric Remanent Strain and its Application on ME-RAM

We have demonstrated a Ni/PMN-PT ME heterostructure providing an electric-field-induced switching between two reversible and permanent magnetic easy axes perpendicular to each other. The tunable remanent strain defines the initial magnetoelastic anisotropy while the giant strain hysteresis reversibly and permanently

Giant piezoelectric strain hysteresis and novel ferroelectric properties of (011) [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT, x≈0.32) single crystals

The ferroelectric (011) [Pb(Mg1/3Nb2/3)O3](1-x)-[PbTiO3]x (PMN-PT, x≈0.32) single crystals show two giant reversible and stable remanent strain states and tunable remanent strain properties are achieved by properly reversing  the electric field from the depolarized direction. The unique piezoelectric strain response, especially

Atomic layer deposition of Pb(Zr,Ti)Ox on 4H-SiC for metal-ferroelectric-insulator-semiconductor diodes

Atomic layer deposited (ALD) Pb(Zr,Ti)Ox (PZT) ultra-thin films were synthesized on an ALD Al2O3 insulation layer on 4H-SiC substrate for metal-ferroelectric-insulator-semiconductor (MFIS) device applications. The as-deposited PZT was amorphous but crystallized into a perovskite polycrystalline structure with a preferred [002]

Conference

T. Wu*, Z. Qian and M. Rinaldi, “Low cost thin film encapsulation for AlN resonators”, 2018 IEEE International Conference on Micro-Electro-Mechanical-Systems (MEMS), Belfast, Jan. 21-25 G. Chen, C. Cassella, T. Wu*, and M. Rinaldi, “Single-Chip Multi-Frequency Wideband Filters Based on