100 research outputs found

    Topological Hall effect in thin films of Mn1.5_{1.5}PtSn

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    Spin chirality in metallic materials with non-coplanar magnetic order can give rise to a Berry phase induced topological Hall effect. Here, we report the observation of a large topological Hall effect in high-quality films of Mn1.5_{1.5}PtSn that were grown by means of magnetron sputtering on MgO(001). The topological Hall resistivity is present up to μ0H4 \mu_{0}H \approx 4~T below the spin reorientation transition temperature, Ts=185T_{s}=185~K. We find, that the maximum topological Hall resistivity is of comparable magnitude as the anomalous Hall resistivity. Owing to the size, the topological Hall effect is directly evident prior to the customarily performed subtraction of magnetometry data. Further, we underline the robustness of the topological Hall effect in Mn\textsubscript{2-x}PtSn by extracting the effect for multiple stoichiometries (x~=~0.5, 0.25, 0.1) and film thicknesses (t = 104, 52, 35~nm) with maximum topological Hall resistivities between 0.76 μΩ0.76~\mu\Omegacm and 1.55 μΩ1.55~\mu\Omegacm at 150~K.Comment: 6 pages, 5 figure

    Thickness dependence of the anomalous Hall effect in thin films of the topological semimetal Co2_2MnGa

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    Topological magnetic semimetals promise large Berry curvature through the distribution of the topological Weyl nodes or nodal lines and further novel physics with exotic transport phenomena. We present a systematic study of the structural and magnetotransport properties of Co2_2MnGa films from thin (20 nm) to bulk like behavior (80 nm), in order to understand the underlying mechanisms and the role on the topology. The magnetron sputtered Co2_2MnGa films are LL212_{\mathrm {1}}-ordered showing very good heteroepitaxy and a strain-induced tetragonal distortion. The anomalous Hall conductivity was found to be maximum at a value of 1138 S/cm, with a corresponding anomalous Hall angle of 13 %, which is comparatively larger than topologically trivial metals. There is a good agreement between the theoretical calculations and the Hall conductivity observed for the 80 nm film, which suggest that the effect is intrinsic. Thus, the Co2_2MnGa compound manifests as a promising material towards topologically-driven spintronic applications.Comment: 7 pages, 5 figures, 1 tabl

    Characterization of individual stacking faults in a wurtzite GaAs nanowire by nanobeam X-ray diffraction

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    Coherent X-ray diffraction was used to measure the type, quantity and the relative distances between stacking faults along the growth direction of two individual wurtzite GaAs nanowires grown by metalorganic vapour epitaxy. The presented approach is based on the general property of the Patterson function, which is the autocorrelation of the electron density as well as the Fourier transformation of the diffracted intensity distribution of an object. Partial Patterson functions were extracted from the diffracted intensity measured along the [0001ˉ000\bar{1}] direction in the vicinity of the wurtzite 001ˉ5ˉ00\bar{1}\bar{5} Bragg peak. The maxima of the Patterson function encode both the distances between the fault planes and the type of the fault planes with the sensitivity of a single atomic bilayer. The positions of the fault planes are deduced from the positions and shapes of the maxima of the Patterson function and they are in excellent agreement with the positions found with transmission electron microscopy of the same nanowire
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