Field and Current Controlled Domain Wall Propagation in Twisted Glass-Coated Magnetic Microwires

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Glass-coated microwires are promising for magnetic applications due to their unique properties.
• Understanding the influence of mechanical stress, such as torsion, is crucial for optimizing their performance.
• Magnetization reversal and domain wall dynamics are key phenomena in magnetic materials.

Purpose of the Study:

• To investigate the torsion effect on field and current-driven magnetization reversal.
• To analyze the impact of torsion on domain wall velocity in various microwire compositions.
• To determine the optimal conditions for enhanced magnetic properties in these microwires.

Main Methods:

• Investigated three types of glass-coated microwires: amorphous FeSiB, amorphous CoFeSiB (near-zero magnetostriction), and nanocrystalline FINEMET.
• Applied torque to induce mechanical deformations (axial compression, circumferential tension).
• Measured magnetization reversal characteristics and domain wall velocity under different conditions.

Main Results:

• Torsion significantly influences anisotropy axes, affecting magnetization reversal and domain wall motion.
• Axial compression is critical for field-driven motion, while circumferential tension affects current-driven motion.
• Optimized CoFeSiB microwires (annealed and twisted) exhibited the lowest switching current (9 mA) and highest domain wall velocity (2300 m/s).

Conclusions:

• Torsion is a key factor in controlling magnetic behavior and domain wall dynamics in microwires.
• The CoFeSiB composition, under specific annealing and twisting, offers superior performance for magnetic applications.
• These findings provide insights for designing advanced magnetic microwire devices.