Propagation of elastic waves in a flexomagnetic solid
arXiv:2602.20485 · doi:10.1016/j.euromechsol.2026.106203
Abstract
Flexomagnetism is the coupling between magnetism and strain gradients and is a technologically relevant phenomenon. We present a theory of elastic wave propagation in a linear elastic flexomagnetic material with microstructure and strain gradient elastic interactions. The expressions of frequency, phase velocity, and group velocity of longitudinal and transverse waves are derived and are shown to depend on the flexomagnetic coefficient and microstructure. We also show that the effect of flexomagnetism and microstructure can lead to some interesting phenomena in wave propagation, which are not observed in classical linear elasticity theory of waves. Specifically, in contrast to classical linear elastic materials, where wave propagation is non-dispersive, flexomagnetic materials with microstructure can exhibit both normal and abnormal dispersion. It is also noteworthy that, in flexomagnetic materials with gradient elasticity, the phase velocities of transverse waves can exceed those of longitudinal waves, which is atypical in classical elasticity. Furthermore, waves can also attenuate for a certain range of wavenumbers that depend on the flexomagnetic coefficient and microstructural parameters. Finally, we explore the possibility of waves exhibiting zero group velocity modes, where waves are non-propagating but have strong local energy confinement, negative group velocity modes, where the wave packet moves in the opposite direction to that of wave propagation, and the phenomenon of wave freezing, where a propagating wave stops in space without diffusing or spreading.
References in corpus (12)
- Time-periodic stiffness modulation in elastic metamaterials for selective wave filtering: theory and experimental investigations
- Frozen light in photonic crystals with degenerate band edge
- Linear magnetoelectric coupling and ferroelectricity induced by the flexomagnetic effect in ferroics
- Curved Magnetism in CrI
- Flexoelectricity in soft elastomers and the molecular mechanisms underpinning the design and emergence of giant flexoelectricity
- Modeling flexoelectricity in soft dielectrics at finite deformation
- Epitaxy, exfoliation, and strain-induced magnetism in rippled Heusler membranes
- Flexoelectric control of a ferromagnetic metal
- Transversal flexoelectric coefficient for nanostructures at finite deformations from first principles
- Dzyaloshinskii-Moriya interaction and magnetic skyrmions induced by curvature
- Missed surface waves in non-piezoelectric solids
- Strain-gradient-induced magnetic anisotropy in straight-stripe mixed-phase bismuth ferrites: An insight into flexomagnetic phenomenon