Disorder driven crossover between anomalous Hall regimes in Fe 3 GaTe 2
The large anomalous Hall conductivity (AHC) of the Fe 3 (Ge,Ga)Te 2 compounds has attracted considerable attention. Here, we expose the intrinsic nature of the AHC in Fe 3 GaTe 2 crystals characterized by high conductivities, which show disorder-independent AHC with a pronounced value 𝜎$^{c}_{𝑥𝑦}$≈ 420 Ω −1 cm −1 . In the low-conductivity regime, we observe the scaling relation 𝜎 𝑥𝑦 ∝ 𝜎$^{1.6}_{𝑥𝑥}$, which crosses over to 𝜎 𝑥𝑦 ≃ 𝜎$^{c}_{𝑥𝑦}$ as 𝜎 𝑥𝑥 increases. Disorder in low-conductivity crystals is confirmed by the broadening of a first-order transition between ferromagnetism and the ferrimagnetic ground state. Through density functional theory (DFT) calculations, we reveal that the dominant sources of Berry curvature are located a few hundred meV below the Fermi energy around the Γ point. Furthermore, Fe 3 GaTe 2 clearly exposes the disorder-induced crossover among distinct AHC regimes, previously inferred from measurements on different ferromagnets located on either side of the crossover region.