The recent discovery of topologically nontrivial behavior in ${\mathrm{Co}}_3{\mathrm{Sn}}_2{\mathrm{S}}_2$ stimulated a notable interest in this itinerant ferromagnet ($T_{\mathrm{C}}=174$ K). The exact magnetic state remains ambiguous, with several reports indicating the existence of a second transition in the range 125–130 K, with antiferromagnetic and glassy phases proposed to coexist with the ferromagnetic phase. Using detailed angle-dependent dc and ac magnetization measurements on large, high-quality single crystals we reveal a highly anisotropic behavior of both the static and dynamic response of ${\mathrm{Co}}_3{\mathrm{Sn}}_2{\mathrm{S}}_2$. It is established that many observations related to sharp magnetization changes when $B\parallel c$ are influenced by the demagnetization factor of a sample. On the other hand, a genuine transition has been found at $T_{\mathrm{P}}=128$ K, with the magnetic response being strictly perpendicular to the $c$ axis and several orders of magnitude smaller than for $B\parallel c$. Calculations using density-functional theory indicate that the ground state magnetic structure consist of magnetic moments canted away from the $c$ axis by a small angle ($\sim 1.5^{\circ }$). We argue that the second transition originates from a small additional canting of moments within the kagome plane, with two equivalent orientations for each spin.

• Received 6 April 2022
• Revised 27 September 2022
• Accepted 1 November 2022

DOI:https://doi.org/10.1103/PhysRevB.106.L180403