Electric Field-Tunable Giant Magnetoresistance (GMR) Sensor with Enhanced Linear Range
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Published on: September 30, 2019
Liqian Wang1, Zhongqiang Hu1, Yuanyuan Zhu1
1Electronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, State Key Laboratory for Mechanical Behavior of Materials , Xi'an Jiaotong University , Xi'an 710049 , China.
Abstract:
The operation mechanism of giant magnetoresistance (GMR) sensors relies on the linear response of the magnetization direction to an external magnetic field. Since the magnetic anisotropy of ferromagnetic layers can be manipulated by a strain-mediated magnetoelectric coupling effect, we propose a tunable GMR magnetic field sensor design that allows for voltage tuning of the linear range and sensitivity. A spin valve structure Ru/CoFe/Cu/CoFe/IrMn/Ru is grown on a PMN-PT (011) substrate, and the magnetization directions of ferromagnetic layers can be controlled by an electric field. An adjustable linear magnetoresistance is therefore induced. Based on the magnetoelectric coupling effect and spin valve, we prepared tunable GMR magnetic field sensors with bridge structures. The linear sensing range of a DC magnetic field is enhanced 6 times by applying an electric field of 14 kV/cm. The electrically tunable GMR sensor fulfills the requirements to work at different magnetic field ranges in the same configuration, therefore exhibiting great potential for applications in the Internet of things.
