基于TMR效应超高灵敏度的复合磁性传感器研究

该项目拟优化和探索基于MgO和尖晶石结构氧化物等新势垒材料、具有高隧穿磁电阻(TMR)的磁性隧道结，研制设计具有超高灵敏度的新型TMR-超导复合磁性传感器。首先研究生长条件、后期退火处理对隧道结界面质量和TMR的影响，获得高质量及高TMR的隧道结材料体系；然后设计不同结构、采用不同线性化方法制备TMR磁性传感器，探讨提高传感器灵敏度和抑制其噪声的途径；研究超导环放大器和磁通聚集器的形状、大小对灵敏度增益系数的影响；最后选择工艺兼容的超导环制备TMR-超导复合传感器，对传感器的灵敏度进行放大实现超弱磁场的探测；进一步集成磁通聚集器和超导环放大器对传感器灵敏度进行双重放大，实现pT和fT量级的磁场探测，为超弱磁场的探测提供一种新的技术方法，拓宽TMR磁性传感器的应用范围。

The aim of this project is to optimise and explore magnetic tunnel junctions (MTJs) with high tunnelling magnetoresistance (TMR) based on MgO and spinel oxide barrier and fabricate TMR-superconductor mixed magnetic sensor with ultra-high sensitivity. Firstly, the influence of growth conditions and post-annealing process on the TMR and interfacial quality will be studied to obtain MTJs with high TMR and quality. Then, magnetic sensors with different structures will be designed and realized by different linearity strategy. The way to improve sensitivity and suppress noise will be explored. The gain factor dependence of geometry and size of the superconductor loop amplifier and magnetic flux concentrator will be studied. At last, the compatible superconductor loop will be integrated with TMR sensor to enhance its sensitivity to detect ultra-low field. Furthermore, the superconductor loop and flux guides will be integrated together to realize dual amplification of sensitivity to detect magnetic field of pT and fT level. This will provide a new technology method to measure ultra-low field and expand the application of TMR magnetic sensor.