First-order reversal curves acquired by a high precision ac induction magnetometer

Area of Science:

• Materials Science
• Magnetism
• Physics

Background:

• Soft magnetic materials exhibit complex irreversible magnetic behavior.
• Conventional characterization methods may not fully capture magnetic viscosity.
• Understanding local magnetic properties is key for material development.

Purpose of the Study:

• To develop and validate a modified ac induction magnetometer setup for precise First-Order Reversal Curve (FORC) measurements.
• To investigate the impact of magnetic viscosity on FORC measurements in soft magnetic materials.
• To enable the study of magnetic viscosity phenomena in soft magnets.

Main Methods:

• Modification of a conventional ac induction magnetometer for high-precision measurements (field sensitivity < 0.005 Oe, magnetization sensitivity < 10(-6) emu).
• Implementation of a novel approach to maintain a constant applied field sweep rate by adjusting frequency for each FORC measurement, compensating for magnetic viscosity.
• Acquisition and analysis of FORC data from soft magnetic samples.

Main Results:

• The modified setup successfully measured FORCs with high precision.
• The results clearly demonstrate the influence of magnetic viscosity on the FORC data.
• The study validates the effectiveness of the adjusted frequency method for accurate FORC acquisition.

Conclusions:

• The developed setup provides a reliable method for characterizing the local irreversible behavior of soft magnetic materials.
• The study highlights the importance of accounting for magnetic viscosity in FORC measurements.
• This work paves the way for further research into magnetic viscosity in soft magnetic materials.