Tuning anomalous Hall effect in bilayers films by the interfacial spin-orbital coupling

Abstract

The anomalous Hall effect (AHE) in the Mn4N/Au bilayers with various Au thicknesses has been investigated. The new scaling including multiple competing mechanisms is employed to analyze the contributions to the AHE. The obvious variations in the skew scattering coefficient α and the two scattering coefficients (β0 + β1 − γ) and (γ − 2β1) in the bilayers reveal that the skew scattering term and the side-jump contribution are dramatically modified, implying that the mechanisms in the bilayers are different from those in the single Mn4N. On further analysis, we find that the coefficient β0 involving the intrinsic mechanism and side-jump contribution also varies, which confirms the experimental results. It is proposed that the modification of the AHE is induced by the spin-orbital coupling from the heavy metal, providing a practical way to tune the AHE.

Microstructure, magnetic and electronic transport properties of reactively facing-target sputtered epitaxial Mn4N films

“…The high domain wall mobility revealed that the potential of Mn 4 N films in current-induced domain wall motion devices [27][28][29]. Besides, the reports about the exchange bias, topological Hall effect and interfacial spin-orbit coupling in Mn 4 N films and its heterostructure also confirmed that Mn 4 N is a promising candidate for spintronic devices [30,31]. Recently, the strong correlation between magnetic anisotropy and inplane strain has been confirmed by growing Mn 4 N films on different substrates [32].…”

Field-Free Deterministic Magnetization Switching with Ultralow Current Density in Epitaxial Au/Fe4N Bilayer Films

“…It is noteworthy that the saturation ρ AH of Au/Fe 4 N bilayer films is considerably larger than that of Fe 4 N single films. Two mechanisms might be related to the enlargement of ρ AH : the first one is a possible magnetic proximity effect (MPE), and through the MPE, the Au layer adjacent to the Au/Fe 4 N interface acquires magnetic features, which could generate AHE just as normal FM conductors do; the other is a modification of the AHE form SHE of Au since AHE and SHE share the same origins, and it has been reported that in many HM/FM bilayer systems, the SHE generated in the HM layer is sufficient to tune the AHE of the FM layer. − However, since no evident differences of M z at zero field in single Fe 4 N films and Au/Fe 4 N bilayer films were observed, it might indicate that the SHE dominates the variation of ρ AH in Au/Fe 4 N bilayers, but the MPE is still hard to exclude completely. In addition, the anomalous Hall loops of both Fe 4 N and Au/Fe 4 N samples drift toward a negative field direction, showing a detectable asymmetry in the coercivity.…”

Progress in ferrimagnetic Mn4N films and its heterostructures for spintronics applications

“…The intrinsic and extrinsic mechanisms of AHE in Mn 4 N films indicate that the AHE is tightly associated with SOC [71][72][73]. The tunable AHE has been observed in Mn 4 N/heavy metal heterostructure [81]. Meanwhile, the THE induced by noncoplanar spin structures in the Mn 4 N based heterostructures also provides an approach to modulate the spin states [64,70].…”

“…Nakagawa et al used Al as underlayers and confirmed the effective influence for the epitaxial growth of Mn 4 N films [38]. In 2018, Wang et al investigated the AHE in the Mn 4 N/Au bilayers [81]. The different thicknesses Au films were deposited on 25 nm thick Mn 4 N films by MBE.…”

“…The Mn 3 NiN films exhibits different magnetic order with the in-plane strain, which paves a new way to manipulate the magnetic properties by piezoelectric effect. Additionally, the modification of AHE and THE in Mn 4 N based heterostructures is induced by different ways, which provides non-magnetic method for manipulation of spin states in magnetic materials [70,81].…”