报告题目：Magnetic Sensors
报告人：Prof.S. H. Liou
时 间：2010年7月2日上午9:00
地 点：曹光彪大楼326会议室
报告摘要：The measurement of magnetic field in the picotesla range is important for a wide range of homeland security, industrial, scientific, and biomedical applications. Many of these applications require sensors with field noise of less than 1 nT/Hz1/2 as well as low cost, small size, low frequency operation, low maintenance, and low power consumption. For example, there is need to develop novel sensor arrays to detect munitions and explosives of concern, monitor the change of the magnetic field of the Earth and space, and detect magnetic biological signals and agents. Currently the few sensors capable of detecting such small fields require cryogenic cooling such as SQUID sensors, require sophisticated detection systems such as atomic magnetometers and fluxgate magnetometers, or have large size and poor low frequency performance such as coil systems.
In this talk, we discuss and show a simple low-power, magnetic sensor system suitable for high sensitivity magnetic field mapping, based on solid-state MTJ devices with minimum detectable fields in the picotesla range at room temperature. The key features of this design are (1) decreasing the noise by the use of a 64 MTJ element bridge, (2) reducing the magnetic noise by annealing of the MTJ sensors in high magnetic field and a hydrogen environment, and (3) increasing the signal by using a external flux-to-field magnetic flux concentrators (MFC).
报告人简介：Prof.S. H. Liou received Ph.D. Physics in 1985, M.A. Physics, 1981, The Johns Hopkins University, Baltimore, Maryland; M.S. Physics, 1979, Florida Institute of Technology, Melbourne, Florida. From 1999 ,he is a professor of University of Nebraska-Lincoln.
Research Interests:
Magnetic sensors-using magnetic tunnel junctions Magnetic Force Microscopy-magnetic domain images and advanced MFM tips for improving magnetic images and local probes. Microcantilever Torque Magnetometer-magnetic characterization of nanostructures. Nanofabrications-cantilevers for single-electron spin microscope, magnetic devices. High Tc Oxide Superconductors and Magnetic Oxides–growth of complex oxide compounds, microstructural characterizations, structure effects in these oxides.
Honors and Awards: 2002 Excellent Presentation Award in the Magnetic Society of Japan,
S. H. Liou, 26th annual conference of MSJ.
欢迎感兴趣的老师、研究生和本科生参加！
2010年6月29日
