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Orbit-Engineered Anisotropic Magnetoresistive Effect for Constructing a Magnetic Sensor with Ultrahigh Sensitivity
Ronggui Zhu1, Lingran Yu1, Xujie Ma1
1Department of Materials Physics and Chemistry, University of Science and Technology Beijing, Beijing 100083, China.
ACS Applied Materials & Interfaces
|February 10, 2022
Summary
Researchers enhanced the anisotropic magnetoresistance (AMR) effect by tuning orbital degrees of freedom in a novel multilayer film. This approach significantly boosts magnetic sensor sensitivity and reliability.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Anisotropic magnetoresistance (AMR) is crucial for magnetic sensor technology.
- Current AMR enhancement methods in films yield ratios below 4% by modulating lattice or charge.
- A new strategy is needed to further improve AMR sensor performance.
Purpose of the Study:
- To enhance the anisotropic magnetoresistance (AMR) effect by manipulating the orbital degree of freedom.
- To develop a novel multilayer film structure for improved magnetic sensing.
- To investigate orbit-governed AMR mechanisms for advanced sensor applications.
Main Methods:
- Fabrication of a Ta/MgO/NiFe/MgO/Ta multilayer film with an inserted oxygen-affinitive Hf layer.
- Modulation of Fe-O orbital hybridization at the MgO/NiFe interface.
- Micromachining the film into a Wheatstone bridge for sensor construction.
Main Results:
- Achieved an enhanced AMR ratio of 4.8% by increasing holes in Fe in-plane symmetric d orbits.
- Demonstrated an ultrahigh sensitivity of 2.7 mV/V/Oe in the fabricated sensor.
- Obtained a low noise detectability of 0.8 nT/√Hz, indicating high reliability.
Conclusions:
- Tuning the orbital degree of freedom offers a novel strategy for strengthening the AMR effect.
- The developed orbit-governed AMR sensor exhibits superior sensitivity and low noise.
- This work provides a new pathway for advancing AMR sensors and exploring other orbit-related physical effects.
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