Field orientation dependent magnetic phases in the Weyl semimetal Co3Sn2S2

Magnetism plays a key role in the emergence of topological phenomena in the Weyl semimetal ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$, which exhibits ferromagnetic interactions along the $c$-axis of the crystal and antiferromagnetic (AFM) interactions within the $ab$ plane. Extensive studies on the temperature dependence of the magnetism with the magnetic field along the $c$-axis have uncovered a number of magnetic phases. Currently, the nature and origins of the reported magnetic phases are under debate. Here we report on magnetic field orientation effects on the magnetism in ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$. The shape of the hysteresis loop of the Hall resistance at a fixed temperature is found to change from rectangular to bow tie-like as the magnetic field is tilted from the $c$-axis toward the $ab$ plane, resembling that reported for magnetic fields along the $c$-axis as the temperature approaches the Curie temperature from below. Unlike their temperature-dependent counterparts, the newly observed bow tie-like hysteresis loops show exchange bias. Our results showcase the contribution of the in-plane AFM interactions to the magnetism in ${\mathrm{Co}}_{3}{\mathrm{Sn}}_{2}{\mathrm{S}}_{2}$ and demonstrate a new way to tune its magnetic phases. They also shed light on the temperature-dependent magnetic phases occurring in the magnetic field along the $c$-axis of the crystal.