Bridging microscale magnetic domain dynamics and macroscopic electromagnetic response in magnetic fibers: A micromagnetic simulation study

Magnetic fibers are promising candidates for smart sensing and electromagnetic composites due to their tunable electromagnetic properties governed by unique magnetic domain structure under external stimuli. This study presents a multiscale computational framework developed using the Micromagnetic Simulation module in COMSOL Multiphysics to investigate the interplay between stress and magnetic response in Co-based magnetic fibers. By coupling micromagnetic simulation with time- and frequency-domain analysis, we reveal how tensile stress modulates the magnetic domain configurations and alters the electromagnetic response. The results demonstrate pronounced stress-magnetoelastic coupling, wherein tensile stress reduces axial magnetization while enhancing circumferential alignment, directly altering ferromagnetic resonance (FMR) characteristics. We further identify a stress-magnetostriction coupling coefficient that manipulates the FMR response to applied stress. Experimental validation through magnetization measurements, magneto-optical Kerr microscopy and impedance measurements supports the simulation predictions. This work provides fundamental insights into magneto-mechanical interactions in magnetic fibers and also provides a computational framework for designing stress-tunable materials optimized for high-frequency applications in sensors, electromagnetic composites, and multifunctional devices.