Tuning anomalous Hall and Nernst effects in MnSb/Cr multilayers

초록

This study investigates the evolution of transverse transport in (MnSb/Cr)n multilayer thin films (n = 1, 2, 4, and 8) by varying the interfacial density while maintaining a constant total MnSb thickness of 40 nm. X-ray diffraction and atomic force microscopy revealed a progressive structural evolution with increasing n, characterized by the emergence of a Mn-rich Mn3Sb phase and modified surface morphology. The saturation magnetization exhibits a systematic modulation from approximately 125 emu cm-3 (n = 1) to 82.7 emu cm-3 (n = 8), reflecting an interfacial magnetic reconfiguration that extends beyond volume dilution. Electrical transport measurements show that the longitudinal resistivity decreases from 1750 to 750 mu Omega & centerdot;cm due to the metallic shunting effect of the Cr layers, whereas the anomalous Hall resistivity follows a more pronounced reduction. A rigorous scaling analysis of rho xy versus rho xx yields an exponent gamma approximate to 1.27, consistent with the intermediate regime where intrinsic Berry curvature and extrinsic interfacial scattering contributions coexist, with the relative weight of extrinsic contributions increasing progressively as the interfacial density increases. Consistently, the anomalous Nernst response and transverse thermoelectric conductivity are modulated by the increasing interfacial density, highlighting the fundamental role of phase-driven structural and magnetic modifications in transverse thermoelectric conversion. These results provide critical design insights for tailoring interface-engineered multilayers for advanced anomalous-transport-based energy harvesting technologies.

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