Fe3GaTe2/Fe3GeTe2异质结的反对称磁阻机制OA

Van der Waals(vdW)magnetic materials have emerged as a promising platform for investigating low-dimensional magnetism and developing next-generation spintronic devices.Among them,all-ferromagnetic heterojunctions,such as the Fe3GaTe2/Fe3GeTe2(FGaT/FGT)system,exhibit intriguing magneto transport phenomena,including multi-step transitions and antisymmetric magnetoresistance(MR)peaks under perpendicular magnetic fields.However,the underlying physical mechanisms governing these complex behaviors remain elusive.This study aims to elucidate the origin of the antisymmetric MR in FGaT/FGT vdW heterojunctions,focusing on the interplay between the anomalous Hall effect(AHE),interfacial oxidation,and temperature-dependent interlayer coupling. High-quality FGaT/FGT heterojunction devices were fabricated using mechanical exfoliation and dry transfer techniques.The magneto transport properties were systematically characterized from 5 K to 190 K using a physical property measurement system(PPMS).The experimental results,combined with an equivalent circuit model analysis,reveal that the antisymmetric MR signal primarily stems from a local non-equilibrium current driven by a mismatch in the AHE voltages generated across the top(FGT)and bottom(FGaT)ferromagnetic layers when their magnetizations are non-collinear.This voltage imbalance significantly modulates the longitudinal resistance(Rxx),producing the characteristic sharp MR peaks near zero field. Furthermore,detailed analysis of the individual FGaT layer uncovers a two-stage magnetization reversal process,attributed to the coexistence of a magnetically distinct interface region,influenced by a naturally formed antiferromagnetic O-FGaT oxide layer,and the FGaT bulk region.This interfacial oxidation induces an exchange bias effect,which is responsible for the observed asymmetry and multi-step transitions in the heterojunction's MR hysteresis loops.Temperature-dependent measurements demonstrate that the antisymmetric MR diminishes upon heating,evolving into a smooth,paramagnetic-like background above 180 K.This transition highlights the suppression of the AHE-driven non-equilibrium transport and the interlayer decoupling as thermal fluctuations reduce magnetic anisotropy. In conclusion,our work demonstrates that the antisymmetric MR in FGaT/FGT heterojunctions arises from the synergistic effects of AHE-induced circulating currents,interface oxidation-mediated exchange bias,and thermally activated layer decoupling.These findings provide a comprehensive understanding of the charge transport mechanisms at magnetic vdW interfaces and offer valuable insights for the design of future multi-state spintronic devices based on interface and domain engineering.