基于MgO磁性隧道结的五种隧穿磁电阻线性传感单元性能比较

Comparison of performance among five types of tunneling magnetoresistance linear sensing units based on MgO magnetic tunnel junction

磁性隧道结经过结构优化和性能提升已成功应用于磁存储、磁传感、磁逻辑等多种自旋电子学器件中.磁传感是利用磁性隧道结的自由层和钉扎层之间特殊的磁结构来实现隧穿磁电阻(TMR)随外加磁场变化而呈现的线性输出.迄今为止,人们基于MgO磁性隧道结已经研发出五种TMR线性传感单元,分别是人工间接双交换耦合型、磁场偏置型、面内/面外垂直型、超顺磁型的TMR线性传感单元.本文梳理了这五种TMR线性传感单元并对它们的磁传感性能进行了系统比较,为人们探索和发现磁敏传感器的相关应用提供了帮助.

Magnetic tunnel junction(MTJ)has been successfully used in spintronic devices,such as magnetoresistive random access memory,tunneling magnetoresistance(TMR)sensor,magnetic logic.In the TMR sensor a special magnetic structure is used between the free layer and the pinned layer of an MTJ to realize a linear output.So far,five types of TMR linear sensing units(TMR-LSNs)have been developed based on MgO MTJs,which are artificial-indirect-double-exchange-coupling-,magnetic-field-biased-,in-plane-,perpendicular-,and superparamagnetic-TMR-LSN,respectively.In this paper,the five types of TMR-LSNs are combed and their magnetic sensing performances are systematically compared with each other.First,the five types of TMR-LSNs each have a linear resistance response to the external magnetic field with a changeable sensitivity,a linear field range and a low frequency noise level.Second,in the five types of TMR-LSNs different magnetic structures are used to realize the same aim that is to obtain the optimized performance parameters,which is of significance for putting TMR sensors into practical applications.Third,the five types of TMR-LSNs are suitable for different application scenarios due to their respective performance parameters.Therefore,we believe that our summarized discussion in this paper will help people to explore and find the relevant applications of TMR sensors based on the five types of TMR-LSNs.