DQMP - Informal Seminar - 04.07.2023 - 13:00 - Arun Kumar Jaiswal

04.07.2023 13:00 – 14:30

Direct observation of strong anomalous Hall effect and proximity-induced ferromagnetism in SrIrO3
Arun Kumar Jaiswal, Karlsruhe Institute of Technology

The complex interplay among the charge, spin, orbital and lattice degrees of freedom at the interfaces between two transition metal oxides (TMOs) have shown enormous potential to generate new ground states otherwise absent in the bulk counterparts. For example, the observation of two-dimensional electron gas at the interface between two band insulators LaAlO3 and SrTiO3 (STO), has revolutionized the field of oxide electronics (1,2). Recently, SrIrO3 (SIO) have gained huge interest as they inherently show strong spin-orbit coupling due to the presence of heavy Ir ions (3). However, the electron correlation in SIO is too weak to host long-range magnetic ordering.
Here, we report on the observation of strong anomalous Hall effect (AHR) and proximity-induced ferromagnetism in SIO when bringing in direct contact to a ferromagnetic insulator LaCoO3 (LCO) (4). The SIO/LCO heterostructures were grown using pulsed laser deposition with atomically sharp and distinct interfaces. The magnetotransport measurements show negative, hysteretic magnetoresistance (MR) and AHR below T¬ = 100K (5). In addition, a fourfold symmetric magnetocrystalline anisotropy was evidenced by anisotropic magnetoresistance (AMR). A four-monolayer thick STO insertion layer in between SIO and LCO completely suppresses magnetic order, demonstrating proximity-induced ferromagnetic exchange in SIO. The exchange mechanism between SIO and LCO is very likely mediated by an interfacial electron transfer, as verified by Hall measurements and electron energy loss spectroscopy.

References-
1)A. Ohtomo, H. Y. Hwang, Nature427, 423 (2004)
2)N. Reyren et al. Science 317,1196-1199 (2007)
3)M. A. Zeb and H.-Y. Kee, Phys. Rev. B 86, 085149 (2012)
4)D. Fuchs et al., Phys. Rev. B, 75, 144402 (2007)
5)A. K. Jaiswal et al., Adv. Mater. 34, 2109163 (2022)



Organisateur: Prof. Andrea Caviglia

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Bâtiment: Ecole de Physique

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