  Magnetic transition metal chalcogenides form an emerging platform for
exploring spin-orbit driven Berry phase phenomena owing to the nontrivial
interplay between topology and magnetism. Here we show that the anomalous Hall
effect in pristine Cr2Te3 thin films manifests a unique temperature-dependent
sign reversal at nonzero magnetization, resulting from the momentum-space Berry
curvature as established by first-principles simulations. The sign change is
strain tunable, enabled by the sharp and well-defined substrate/film interface
in the quasi-two-dimensional Cr2Te3 epitaxial films, revealed by scanning
transmission electron microscopy and depth-sensitive polarized neutron
reflectometry. This Berry phase effect further introduces hump-shaped Hall
peaks in pristine Cr2Te3 near the coercive field during the magnetization
switching process, owing to the presence of strain-modulated magnetic domains.
The versatile interface tunability of Berry curvature in Cr2Te3 thin films
offers new opportunities for topological electronics.
