Enhancement of the anomalous Hall effect in Ni thin films by artificial interface modification

Sun

et al. 2020

Adv Funct Materials

Anomalous Hall effect (AHE) can be induced by intrinsic mechanism due to the band Berry phase and extrinsic one arising from the impurity scattering. The recently discovered magnetic Weyl semimetal Co3Sn2S2 exhibits a large intrinsic anomalous Hall conductivity (AHC) and a giant anomalous Hall angle (AHA). The predicted energy dependence of the AHC in this material exhibits a plateau at 1000 Ω-1 cm-1 and an energy width of 100 meV just below EF, thereby implying that the large intrinsic AHC will not significantly change against small-scale energy disturbances such as slight p-doping. Here, we successfully trigger the extrinsic contribution from alien-atom scattering in addition to the intrinsic one of the pristine material by introducing a small amount of Fe dopant to substitute Co in Co3Sn2S2. Our experimental results show that the AHC and AHA can be prominently enhanced up to 1850 Ω-1 cm-1 and 33%, respectively, owing to the synergistic contributions from the intrinsic and extrinsic mechanisms as distinguished by the TYJ model. In particular, the tuned AHA holds a record value in low fields among known magnetic materials. This study opens up a pathway to engineer giant AHE in magnetic Weyl semimetals, thereby potentially advancing the topological spintronics/Weyltronics.

“…This is the so-called TYJ scaling, [27] which has been used to successfully distinguish these three contributions in many systems. [34][35][36][37][38][39] In the equation,…”

Section: Separation Of Intrinsic and Extrinsic Mechanisms Via Applicamentioning

confidence: 99%

33% Giant Anomalous Hall Current Driven by Both Intrinsic and Extrinsic Contributions in Magnetic Weyl Semimetal Co₃Sn₂S₂

Zeng

Sun

et al. 2020

Adv Funct Materials

“…The saturation magnetization of the samples could be estimated by the magnetic saturation field in Hall resistivity curves, since the samples have in-plane magnetization (demagnetization factor N = 1 in out-of-plane direction), as shown in Fig. 3 Since we observed the variation of anomalous Hall resistivity for these samples with different seed layers, one may quest if the variation is caused by the interfacial spin-orbital coupling [25,26] or interfacial modification [27] other than the surface roughness. We then prepared several samples with the same roughness but different interfacial spin-orbital coupling.…”

Section: Anomalous Hall Effect Scaling Analysis 233mentioning

confidence: 92%

Effect of surface roughness on the anomalous Hall effect in Fe thin films

Wen

et al. 2020

Phys. Rev. B

Surface roughness plays an important role on the magnetotransport properties of thin films, especially in ultrathin films. In this work, we prepared Fe thin films with various surface roughness by using different seed layers and studied the electrical transport and anomalous Hall effect. By tuning surface roughness scattering, the longitudinal resistivity (ρ xx ) measured at 5 K increases by one order of magnitude and the corresponding anomalous Hall resistivity (ρ AHE ) increases by three times with increasing roughness. The intrinsic, skewscattering, and side-jump contributions to ρ AHE were separated from our data. The anomalous Hall angle depends on the surface roughness, which may be of importance to the material engineering for achieving large spin Hall angle.

“…13 Jin et al showed an enhancement of anomalous Hall effect (AHE) by interfacial modification. 14 Our recent work shows anomalous Hall effect can be greatly enhanced by inserting an ultrathin CoO layers at MgO/[Co/Pt] 3 bottom and [Co/Pt] 3 /MgO top interfaces. 15 In this paper, the interfacial structures were characterized by Xray photoelectron spectroscopy (XPS), showing that the MgO/Co interface and Co/MgO interface including chemical states play a dominant role on spin-dependent transport, leading to different anomalous Hall behavior.…”

mentioning

confidence: 93%

Effect of MgO/Co interface and Co/MgO interface on the spin dependent transport in perpendicular Co/Pt multilayers

Journal of Applied Physics

Yang

Wang

et al. 2014

Analysis of oxygen induced anisotropy crossover in Pt / Co / M Ox trilayers J. Appl. Phys.Effect of the metal/oxide interface on spin-dependent transport properties in perpendicular [Co/Pt] 3 multilayers was investigated. The saturation Hall resistivity (q xy ) is significantly increased by 45% with 1.4 nm thick CoO layer inserted at the top Co/MgO interface; whereas it is increased only 25% with 1 nm thick CoO layer at the bottom MgO/Co interface. The interfacial structures characterized by X-ray photoelectron spectroscopy show that the MgO/Co interface and Co/MgO interface including chemical states play a dominant role on spin-dependent transport, leading to different anomalous Hall behavior. V C 2014 AIP Publishing LLC.