Enhanced Spin Pumping and Magnetization Dynamics in Ni80Fe20/MoS2 Nanoscale-Thick Stacks via Interface Modification for Spintronics Applications

Abstract

Materials possessing pronounced spin–orbit coupling (SOC) are fundamental to the development of spin–orbit torque-driven magnetic memory devices, as they facilitate efficient manipulation of spin currents essential for device operation. Transition metal dichalcogenides are promising candidates for such applications because of their inherently high SOC strength. This work investigates the interfacial spin pumping effect between a monolayer of molybdenum disulfide (ML-MoS₂) and Ni₈₀Fe₂₀ (Py) thin films, using broadband ferromagnetic resonance (FMR) spectroscopy. FMR measurements reveal a notable enhancement in the effective damping factor for the ML-MoS₂/Py (Pt = 0 nm) interface compared to the reference Py thin films, attributed to spin pumping across the ML-MoS₂/Py interface. To quantify spin pumping efficiency, we insert a high SOC platinum (Pt) interlayer at the ML-MoS₂/Py interface and systematically vary its thickness (1, 2, and 5 nm). This enables the evaluation of key spin transport parameters, including the enhancement of the effective damping parameter and the effective spin mixing conductance, which reflects the transfer of spin angular momentum from Py to the ML-MoS₂, thereby allowing us to determine the effective spin current density. The results indicate that ML-MoS₂ in combination with Pt layers of 1, 2, and 5 nm thickness is well suited for spintronic applications with promising potential for energy-efficient memory and logic devices.