SBIR Phase I: Magnetic-Tunneling-Junction Sensors for Sensitive Magnetic Microscopes

这个小企业创新研究第一阶段项目将开发磁隧道结（MTJ）传感器，专门为灵敏的磁显微镜设计和优化。这些小型化的传感器，通过展示巨磁电阻（GMR）和在环境条件下工作，将使磁显微镜的成像，表征和研究样品产生微小的磁场在微观水平的结构成为可能。显微镜将“看到”由奔腾芯片的电流分布产生的局部场图像，揭示任何操作异常。它将绘制亚微米粒子的磁畴结构。研究人员还可以使用显微镜来研究基本的材料性质，如超导体通量线结构和动力学、生物磁学等。预计MTJ传感器具有优于自旋阀和霍尔传感器的性能。第一阶段将解决显微镜发展的关键问题：1)磁噪声；2)磁力联轴器；3)微磁学。本项目第二期将建造新一代磁显微镜样机。MTJ传感器在磁性显微镜中用于半导体芯片和磁性薄膜和介质的非侵入性表征。它们还可以应用于数据存储，遥感，汽车控制，电子导航和罗盘以及无损评估中的读/写磁头。

This Small Business Innovation Research Phase I project will develop magnetic tunneling junction (MTJ) sensors, specially designed and optimized for a sensitive magnetic microscope. These miniaturized sensors, by exhibiting giant magnetoresistance (GMR) and working at ambient conditions, will enable construction of a magnetic microscope for imaging, characterizing, and investigating samples that generate minute magnetic fields at microscopic levels. The microscope will "see" local field images resulting from the electrical current distribution of a Pentium chip, revealing any operational abnormality. It will map magnetic domain structures of submicron particles. Researchers can also use the microscope to investigate basic material properties such as superconductor flux-line structures and dynamics, biomagnetism, etc. MTJ sensors are expected to have properties superior to spin-valves and Hall sensors. Phase I will tackle issues critical to the microscopes development: 1) magnetic noise; 2) magnetic couplings; and 3) micromagnetics. Phase II of this project will build a prototype of a new generation of magnetic microscope.MTJ sensors have applications in magnetic microscopy for non-invasive characterization of semiconductor chips and magnetic films and media. They can also be applied to read/write heads in data storage, remote-sensing, automotive control, electronic navigation and compassing, and non-destuctive evaluation.