November 07, 2022
Minneapolis, United States
Proximity Enhanced Anomalous Hall Transport in Biphase Iron Oxide/Tungsten Disulfide Heterostructures
Interfacial properties of two-dimensional (2D) van der Waals material/magnetic material heterostructures are crucial for applications in spintronics and valleytronics. Inspired by the recent observation of room temperature ferromagnetic ordering in 2D MoS2 induced by the ferrimagnetic yttrium iron garnet (YIG) and the antiferromagnetic exchange coupling between MoS2 and YIG in a MoS2 / YIG heterostructure 1, investigation into the proximity-mediated spin properties of such heterostructures has become a topic of global interest. Nonetheless, a full understanding of the magnetic proximity effect (MPE) and its temperature and magnetic field evolution in these systems is lacking. In this study, we have used biphase iron oxide (Fe3O4 + Fe2O3) as the magnetic layer and the MPE has been probed in Pt / Tungsten Disulfide / biphase iron oxide heterostructures through a comprehensive investigation of their magnetic and transport properties using magnetometry, transverse susceptibility, four-probe resistivity, and anomalous Hall effect (AHE) measurements. Density functional theory (DFT) calculations are performed to complement the experimental findings. We find that the presence of monolayer Tungsten Disulfide flakes reduces the magnetization of biphase iron oxide and hence the total magnetization of Pt / Tungsten Disulfide / biphase iron oxide above the Verwey transition temperature of Fe3O4 (TV). However, the enhanced magnetization is achieved at T < TV. In the latter case, a comparative analysis of the transport properties of the Pt / Tungsten Disulfide / biphase iron oxide heterostructure and the Pt / biphase iron oxide heterostructructures from the AHE measurements reveals a ferromagnetic coupling at the Tungsten Disulfide / biphase iron oxide interface. Our study forms the foundation for understanding MPE-mediated interfacial properties and paves a new pathway for designing 2D van der Waals material/magnet heterostructures for spin-based device applications
References (1) Tsai, S. P.; Yang, C. Y.; Lee, C. J.; Lu, L. S.; Liang, H. L.; Lin, J. X.; Yu, Y. H.; Chen, C. C.; Chung, T. K.; Kaun, C. C.; Hsu, H. S.; Huang, S. Y.; Chang, W. H.; He, L. C.; Lai, C. H.; Wang, K. L. Room-Temperature Ferromagnetism of Single-Layer MoS2 Induced by Antiferromagnetic Proximity of Yttrium Iron Garnet. Advanced Quantum Technologies 2021, 4, 2000104. https://doi.org/10.1002/qute.202000104.