Multiple magnetic phase transitions and magnetotransport in antiferromagnet Mn5Si3 bulk single crystal

Abstract

Mn5Si3 is a metallic antiferromagnet with rich temperature- and field-driven multiple transitions. Using Cu-flux-grown bulk single crystals, we uncover pronounced anomalies in resistivity and magnetoresistance (MR) below ∼100 K, indicating successive reconstructions of the antiferromagnetic state. The longitudinal MR shows a strong low-field response with characteristic field scales. Angle-dependent magnetoresistance (ADMR) under in-plane field rotation provides a symmetry-resolved fingerprint: a 2 + 4 + 6 Fourier-series decomposition reveals a clear redistribution of symmetry weights, including a marked enhancement of the sixfold component at low temperature under high field. Reproducible non-sinusoidal features at 20 K and 7 T further suggest rotation-induced rearrangements beyond a static description. These results establish symmetry-sensitive magnetotransport, including ADMR, as an effective probe of complex antiferromagnetic reconstructions in Mn5Si3.