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arXiv · 2508.20710

Magnetism and nonlinear charge transport in NiFe2O4/γ-Al2O3/SrTiO3 heterostructure: Toward Spintronic Applications

Amit Chanda·Thor Hvid-Olsen·Christina Hoegfeldt·Anshu Gupta·Alessandro Palliotto·Fardin Ghaffari-Tabrizi·Maja A. Dunstan·Kasper S. Pedersen·Dae-Sung Park·Damon J. Carrad·Thomas Sand Jespersen·Felix Trier
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Abstract

We present the synthesis and study of the magnetic and electronic properties of NiFe2O4/γ-Al2O3/SrTiO3 heterostructure. The γ-Al2O3/SrTiO3 interface hosts a high-mobility two-dimensional electron gas (2DEG) with large spin-orbit coupling, making it promising for spintronics applications if it can be coupled to a suitable source of spin currents. Here, we synthesize a ferrimagnetic insulating NiFe2O4(001) layer on γ-Al2O3(001)/SrTiO3(001) using a low-temperature reactive sputtering at 150 deg C without compromising the mobility and charge carrier density of the 2DEG at the γ-Al2O3(001)/SrTiO3(001) interface. The sheet resistance of both γ-Al2O3/SrTiO3 and NiFe2O4/γ-Al2O3/SrTiO3 exhibits metallic behavior down to cryogenic temperatures, with a low temperature upturn driven by the Kondo-like scattering. Most importantly, NiFe2O4/γ-Al2O3/SrTiO3 behaves as a magnetic diode at low temperatures, and its rectification performance increases significantly with increasing magnetic field strength giving rise to a robust magneto-electronic rectification effect at low temperatures, which provides a first step towards the development of all-oxide heterostructures capable of efficient spin-charge conversion.

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Amit Chanda, Thor Hvid-Olsen, Christina Hoegfeldt, Anshu Gupta, Alessandro Palliotto, Fardin Ghaffari-Tabrizi, Maja A. Dunstan, Kasper S. Pedersen, Dae-Sung Park, Damon J. Carrad, Thomas Sand Jespersen, Felix Trier. 2026-01-31. Magnetism and nonlinear charge transport in NiFe2O4/γ-Al2O3/SrTiO3 heterostructure: Toward Spintronic Applications. https://doi.org/10.1002/adfm.202526637

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