RESUMO
Spin-to-charge conversion at the interface between magnetic materials and transition metal dichalcogenides has drawn great interest in the research efforts to develop fast and ultralow power consumption devices for spintronic applications. Here, we report room temperature observations of spin-to-charge conversion arising from the interface of Ni80Fe20 (Py) and molybdenum disulfide (MoS2). This phenomenon can be characterized by the inverse Edelstein effect length (λIEE), which is enhanced with decreasing MoS2 thicknesses, demonstrating the dominant role of spin-orbital coupling (SOC) in MoS2. The spin-to-charge conversion can be significantly improved by inserting a Cu interlayer between Py and MoS2, suggesting that the Cu interlayer can prevent magnetic proximity effect from the Py layer and protect the SOC on the MoS2 surface from exchange interactions with Py. Furthermore, the Cu-MoS2 interface can enhance the spin current and improve electronic transport. Our results suggest that tailoring the interface of magnetic heterostructures provides an alternative strategy for the development of spintronic devices to achieve higher spin-to-charge conversion efficiencies.
RESUMO
The exploration initiated by the discovery of the topological insulator (BixSb1-x)2Te3 has extended to unlock the potential of quantum anomalous Hall effects (QAHEs), marking a revolutionary era for topological quantum devices, low-power electronics, and spintronic applications. In this study, we present the epitaxial growth of Cr-doped (Bi0.4Sb0.6)2Te3 (Cr:BST) thin films via molecular beam epitaxy, incorporating various Cr doping concentrations with varying Cr/Sb ratios (0.025, 0.05, 0.075, and 0.1). High-quality crystalline of the Cr:BST thin films deposited on a c-plane sapphire substrate has been rigorously confirmed through reflection high-energy electron diffraction (RHEED), X-ray diffraction (XRD), and high-resolution transmission electron microscopy (HRTEM) analyses. The existence of a Cr dopant has been identified with a reduction in the lattice parameter of BST from 30.53 ± 0.05 to 30.06 ± 0.04 Å confirmed by X-ray diffraction, and the valence state of Cr verified by X-ray photoemission (XPS) at binding energies of ~573.1 and ~583.5 eV. Additionally, the influence of Cr doping on lattice vibration was qualitatively examined by Raman spectroscopy, revealing a blue shift in peaks with increased Cr concentration. Surface characteristics, crucial for the functionality of topological insulators, were explored via Atomic Force Microscopy (AFM), illustrating a sevenfold reduction in surface roughness as the Cr concentration increased from 0 to 0.1. The ferromagnetic properties of Cr:BST were examined by a superconducting quantum interference device (SQUID) with a magnetic field applied in out-of-plane and in-plane directions. The Cr:BST samples exhibited a Curie temperature (Tc) above 50 K, accompanied by increased magnetization and coercivity with increasing Cr doping levels. The introduction of the Cr dopant induces a transition from n-type ((Bi0.4Sb0.6)2Te3) to p-type (Cr:(Bi0.4Sb0.6)2Te3) carriers, demonstrating a remarkable suppression of carrier density up to one order of magnitude, concurrently enhancing carrier mobility up to a factor of 5. This pivotal outcome is poised to significantly influence the development of QAHE studies and spintronic applications.