Scanning magnetoresistive microscopy: An advanced characterization tool for magnetic nanosystems

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Magnetic imaging techniques are crucial for understanding magnetic materials.
• Existing methods like magnetic force microscopy have limitations in signal detection and field application.
• Advancements in sensor technology offer opportunities for improved magnetic microscopy.

Purpose of the Study:

• To present an advanced scanning magnetoresistive microscopy (SMRM) technique.
• To highlight the capabilities and advantages of SMRM for magnetic imaging and probing.
• To demonstrate the practical applications of SMRM through various experimental examples.

Main Methods:

• Utilizing state-of-the-art hard disk drive recording heads as sensors.
• Employing tunneling magnetoresistive sensors for high spatial resolution.
• Integrating capabilities for local bipolar magnetic field pulse application (up to 10 kOe, DC-1 GHz).
• Equipping the system with a heating stage and external magnetic field units.

Main Results:

• SMRM achieves spatial resolution comparable to traditional magnetic force microscopes.
• The technique directly detects magnetic signals proportional to out-of-plane stray fields with negligible sensor interference.
• Demonstrated successful temperature-dependent studies on L1(0) FeCuPt thin films.
• Successfully imaged magnetic vortex states and demonstrated their manipulation using local field pulses.

Conclusions:

• SMRM is a robust and versatile technique for advanced magnetic imaging and probing.
• Its ability to apply local magnetic fields and detect pure magnetic signals opens new avenues for materials research.
• SMRM provides a powerful tool for investigating magnetic phenomena and manipulating magnetic microstructures.