Curvature-induced spin-wave dynamics in Ni ₃₀ Co ₇₀ magnetic nanotubes: angular ferromagnetic resonance, multi-mode excitation, and magnonic control

Abstract Curvilinear magnetism offers a powerful route to engineer spin-wave phenomena beyond the limitations of planar architectures. In Curvilinear systems geometry itself acts as an active control parameter. Magnetic nanotubes (MNTs) represent an archetypal three-dimensional platform. In MNTs curvature induces emergent anisotropies, symmetry breaking, and nonreciprocal spin-wave transport without relying on interfacial Dzyaloshinskii–Moriya interactions. In this manuscript, we investigate curvature-engineered spin-wave dynamics in thick-walled Ni 30 Co 70 magnetic nanotubes using broadband, angular-dependent ferromagnetic resonance spectroscopy. We observe pronounced splitting and hybridization of spin-wave modes that are absent in thin shells and planar films. Our measurements revealing the decisive role of finite shell thickness and curvature. The angular evolution of the spectra exhibits a maximum mode splitting near φ H =60 0 . These modes arises from a competition between short-range exchange and curvature-enhanced dipolar interactions. Quantitative analysis using Kittel framework results discrete spin-wave wave vectors in the range ~0.25-0.52 nm -1 . Observed values are in excellent agreement with existing literature based on nanotubes. Our results provide ensemble-level experimental evidence of curvature-induced lifting of mode hybridization, and spectral asymmetry in magnetic nanotubes. By establishing curvature as a robust and scalable design parameter for tailoring magnon spectra. Also, this work advances both the fundamental understanding of spin-wave physics in three-dimensional shells and the realization of reconfigurable, low-loss magnonic circuitry based on curvilinear nanomagnets.