Suppression and reemergence of directional transport across the ferromagnetic transition in SrRuO$_3$

Abstract

SrRuO$_3$ is a canonical itinerant ferromagnet that continues to serve as a fertile platform for exploring spin-orbit coupled transport and topological responses in correlated oxide metals. Here, we investigate a (110)-oriented epitaxial SrRuO3 thin film on DyScO$_3$, where crystallographic anisotropy allows for symmetry-resolved charge transport along orthogonal in-plane directions. We uncover two principal findings. First, the resistance above the Curie temperature $T_{c,on}\approx 165$ K exhibits strong anisotropy, consistent with directionally dependent spin-fluctuation scattering. Below $T_{c,on}$, this anisotropy nearly vanishes, despite persistent structural inequivalence, due to isotropic electron-magnon and electron-electron scattering processes. Second, the application of a magnetic field reveals a striking directional contrast in the linear magnetoresistance (MR): it remains negative and saturates along [001], but changes sign and becomes positive along $[1\bar{1}0]$ below $T_0=145$ K. In contrast, the quadratic MR term is identical for both directions and peaks near $T_{\mathrm{OHE}}^*=155$ K, where the ordinary Hall coefficient crosses zero, consistent with carrier compensation under a two-band scenario. A sign change in the anomalous Hall signal at $T_{\mathrm{AHE}}^*=150$ K is consistent with a temperature-dependent redistribution of Berry-curvature contributions near the Fermi level. These results establish ferromagnetic ordering as the primary driver of the observed directional magnetotransport in SrRuO$_3$.