Performance of Fluxgate Magnetometer with Cu-Doped CoFeSiB Amorphous Microwire Core

Area of Science:

• Materials Science
• Condensed Matter Physics
• Sensor Technology

Background:

• Fluxgate magnetometer noise performance is critically dependent on the crystal structure of its core materials.
• Amorphous microwires, specifically CoFeSiB, are utilized in fluxgate sensors, but their noise characteristics require optimization.
• Understanding the impact of elemental doping on the microstructure and magnetic properties of these microwires is essential for sensor improvement.

Purpose of the Study:

• To investigate the effects of copper (Cu) doping on the performance of CoFeSiB amorphous microwires used in fluxgate magnetometers.
• To establish the relationship between Cu doping levels, nanocrystalline formation, magnetic properties, and sensor noise performance.
• To identify optimal Cu doping concentrations for reducing noise and enhancing the stability of amorphous wire sensors.

Main Methods:

• CoFeSiB amorphous microwires with varying Cu doping ratios were fabricated using melt-extraction technology.
• Microstructural analysis was performed using transmission electron microscopy (TEM) to examine nanocrystalline growth.
• Magnetic performance of the microwires and noise characteristics of the fluxgate sensors were systematically evaluated.

Main Results:

• Cu doping was found to enhance nanocrystalline formation by promoting positive mixing enthalpy and reducing atomic radius differences.
• Differential scanning calorimetry (DSC) indicated that Cu doping decreases the glass formation capacity of the alloy system.
• A Cu doping concentration of 1% resulted in superior soft magnetic properties and the best noise performance for the fluxgate sensors, attributed to the interplay between nanocrystalline structure and magnetic domains.

Conclusions:

• Cu doping is an effective strategy for reducing microscopic defects and enhancing soft magnetic properties in CoFeSiB amorphous microwires, leading to improved fluxgate sensor noise performance.
• Optimizing Cu doping levels, particularly around 1%, is crucial for achieving stable and high-performance amorphous wire sensors.
• The study demonstrates that controlled Cu doping offers a superior method for preparing amorphous wires with consistent and enhanced magnetic characteristics for sensor applications.