The electrical switching of magnetization through spin–orbit torque (SOT)1 holds promise for application in information technologies, such as low-power, non-volatile magnetic memory. Materials with strong spin–orbit coupling, such as heavy metals2,3,4 and topological insulators5,6, can convert a charge current into a spin current. The spin current can then execute a transfer torque on the magnetization of a neighbouring magnetic layer, usually a ferromagnetic metal like CoFeB, and reverse its magnetization. Here, we combine a ferromagnetic transition metal oxide7 with an oxide with strong spin–orbit coupling8 to demonstrate all-oxide SOT devices. We show current-induced magnetization switching in SrIrO3/SrRuO3 bilayer structures. By controlling the magnetocrystalline anisotropy of SrRuO3 on (001)- and (110)-oriented SrTiO3 (STO) substrates, we designed two types of SOT switching schemes. For the bilayer on the STO(001) substrate, a magnetic-field-free switching was achieved, which remained undisturbed even when the external magnetic field reached 100 mT. The charge-to-spin conversion efficiency for the bilayer on the STO(110) substrate ranged from 0.58 to 0.86, depending on the directionality of the current flow with respect to the crystalline symmetry. All-oxide SOT structures may help to realize field-free switching through a magnetocrystalline anisotropy design.
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The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.
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The research is supported by the Singapore National Research Foundation under CRP Award no. NRF-CRP10-2012-02 and the Singapore Ministry of Education MOE2018-T2-2-043 and MOE 2018-T2-1-019, AMEIRG18-0022 and A*STAR IAF-ICP 11801E0036. J.C. is a member of the Singapore Spintronics Consortium (SG-SPIN). C.L. acknowledges the financial support from the Lee Kuan Yew Postdoctoral Fellowship through the Singapore Ministry of Education Academic Research Fund Tier 1 (Grant no. R-284-000-158-114).
The authors declare no competing interests.
Peer review information: Nature Nanotechnology thanks Lior Klein and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.
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Liu, L., Qin, Q., Lin, W. et al. Current-induced magnetization switching in all-oxide heterostructures. Nat. Nanotechnol. 14, 939–944 (2019). https://doi.org/10.1038/s41565-019-0534-7
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