We investigated temperature-driven spin reorientation (SR) in the itinerant kagome magnet Fe3Sn2 using high-resolution synchrotron x-ray diffraction, neutron diffraction, magnetometry, and magnetic force microscopy (MFM), further supported by phenomenological analysis. Our study reveals a crossover from the state with easy-plane anisotropy to the high-temperature state with uniaxial easy-axis anisotropy taking place between ∼40−130~ K through an intermediate easy-cone (or tilted spin) state. This state, induced by the interplay between the anisotropy constants K1 and K2, is clearly manifested in the thermal evolution of the magnetic structure factor, which reveals a gradual change of the SR angle θ between 40−130~K. We also found that the SR is accompanied by a magnetoelastic effect. Zero-field MFM images across the SR range show a transformation in surface magnetic patterns from a dendritic structure at 120~K, to domain wall dominated MFM contrast at 40~K.
@article{arxiv.2502.03239,
title = {Easy-cone state mediating the spin reorientation in topological kagome magnet Fe$_3$Sn$_2$},
author = {L. Prodan and D. M. Evans and A. S. Sukhanov and S. E. Nikitin and A. A. Tsirlin and L. Puntingam and M. C. Rahn and L. Chioncel and V. Tsurkan and I. Kezsmarki},
journal= {arXiv preprint arXiv:2502.03239},
year = {2025}
}