Magnetoresistive sensors based on the elasticity of domain walls

TL;DR

This paper introduces a novel magnetoresistive sensor mechanism that detects magnetic fields by measuring the elastic expansion of magnetic domain walls, allowing for tunable sensitivity and range without altering material properties.

Contribution

It proposes a new sensor design based on elastic domain wall expansion, enabling adjustable performance and improved integration over existing magnetoresistive sensors.

Findings

Sensor sensitivity and range can be tuned via device geometry.

The mechanism is theoretically explained and experimentally supported.

Simulations verify the sensor's functionality and performance.

Abstract

Magnetic sensors based on the magnetoresistance effects have a promising application prospect due to their excellent sensitivity and advantages in terms of the integration. However, competition between higher sensitivity and larger measuring range remains a problem. Here, we propose a novel mechanism for the design of magnetoresistive sensors: probing the perpendicular field by detecting the expansion of the elastic magnetic Domain Wall (DW) in the free layer of a spin valve or a magnetic tunnel junction. Performances of devices based on this mechanism, such as the sensitivity and the measuring range can be tuned by manipulating the geometry of the device, without changing the intrinsic properties of the material, thus promising a higher integration level and a better performance. The mechanism is theoretically explained based on the experimental results. Two examples are proposed and their functionality and performances are verified via micromagnetic simulation.