Current-Induced Suppression of Topological Hall Effect in Pt/NiCo₂O₄Heterostructure Over Wide Temperature Range

Magnetic Skyrmions are promising next generation magnetic storage due to their nanoscale size, which could enable high-density information storage, and their low threshold for current-driven motion, which promises low energy consumption. Skyrmions-hosting bilayer heterostructure not only serves as a platform for spintronic devices while stabilizing small Skyrmions. In this work, we investigated a bilayer heterostructure of Pt/ NiCo₂O₄ (NCO), where above-room-temperature ferrimagnetic conductor NCO possesses magnetic properties that support small Skyrmions, including large perpendicular magnetic anisotropy^[1], moderate exchange interaction, and modest magnetization. Topological Hall effect (THE) is observed over a wide temperature range (2 - 350 K), indicating the stabilization of small Skyrmions ( 10 nm) due to interfacial Dzyaloshinskii-Moriya interaction. Additionally, we show that THE decreases with increasing current densities (10⁷ – 10⁹ A/m²), demonstrating current-driven Skyrmions motion and the emergence of the electric field in the Skyrmions phase. These results reveal crucial insights into Skyrmion manipulation in heavy metal/conducting ferrimagnetic oxide thin films, with potential for high-density, low-power spintronic devices and energy-efficient data storage.



Acknowledgement:

This work is supported by National Science Foundation (NSF) through EPSCoR RII Track-1: Emergent Quantum Materials and Technologies (EQUATE), Award No. OIA-2044049 (UNL).

[1] C. Mellinger, J. Waybright, X. Zhang, C. Schmidt, X. Xu, Phys Rev B 2020, 101, 14413.