Magnetic anisotropy and magnetic phase diagram of a kagome antiferromagnet Fe1-xCoxSn

Abstract

We investigate the anisotropic magnetic response in a kagome antiferromagnetic compound Fe1-xCoxSn (x = 0, 0.04, 0.06, 0.14). The magnetic behaviors of three distinct spin orderings, namely the planar, tilted, and axial spin states, are examined under various conditions, including doping rate, temperature, and magnetic fields. We confirm that the magnetic susceptibility of all three spin states has significant anisotropy, which depends on both the magnitude and direction of the applied magnetic field. The planar and axial states show scaling behavior in magnetic susceptibility, while the tilted state does not. Furthermore, employing the differential magnetic susceptibility, we observe that the axial spins display discontinuous spin-flop transitions, while the planar and tilted spins exhibit a continuous spin reorientation. The magnetic phase diagrams, summarizing our observations, highlight the anisotropic nature of magnetic behaviors in the Fe1-xCoxSn system. These diagrams clearly show that the magnetic responses are not overlapping and follow distinct mechanisms in their interaction with magnetic fields. We suggest that the axial state may arise due to the dopants as an obstacle within the kagome lattice, as evidenced by similar magnetic behaviors in Fe0.96Ni0.06Sn. © 2023 Elsevier B.V.