In-situ Instrumental Setup for Influence Study of Hard-axis Bias Magnetic Field on MR transfer curves of sing MTJ sensor and MTJs array sensor

TL;DR

This paper introduces a custom measurement setup for characterizing MR sensors, analyzing how hard-axis bias magnetic fields influence their transfer curves, and optimizing fields for linear sensor response.

Contribution

It presents a novel in-situ instrumental setup with Helmholtz coils for in-depth MR sensor characterization and compares single and array MTJ sensors under bias fields.

Findings

Optimal hard-axis magnetic fields were identified for linear response.

The influence of bias fields on MR transfer curves was systematically studied.

Comparison between single and array MTJ sensors was conducted.

Abstract

Establishment of home-made measurement setups for the characterization of MR sensor is proposed and described here. The MR loops of MR sensors can be obtained with the instrument using two-point probe measurement and four-point probe measurement. Two pairs of Helmholtz coils can supply a hard-axis magnetic field and a soft-axis magnetic field for the sensor. The single MTJ sensor and MTJs array sensor in Wheatstone bridge were characterized and compared here. The influence of hard-bias magnetic field on MR transfer curves of sing MTJ sensor and MTJs array sensor are investigated. The corresponding optimal hard-axis magnetic fields were obtained through Helmholtz coils to eliminate the hysteresis for linear response of single MTJ sensor and MTJs array sensor.