Modulated Transport Behavior of Two-Dimensional Electron Gas at Ni-Doped LaAlO₃/SrTiO₃ Heterointerfaces

Abstract

Modulating transport behaviors of two-dimensional electron gases are of critical importance for applications of the next-generation multifunctional oxide electronics. In this study, transport behaviors of LaAlO/SrTiO heterointerfaces modified through the Ni dopant and the light irradiation have been investigated. Through the Ni dopant, the resistances increase significantly and a resistance upturn phenomenon due to the Kondo effect is observed at T < 40 K. Under a 360 nm light irradiation, the interfaces exhibit a persistent photoconductivity and a suppressed Kondo effect at low temperature due to the increased mobility measured through the photo-Hall method. Moreover, the relative changes in resistance of interfaces induced by light are increased from 800 to 6600% at T = 12 K with increasing the substitution of Ni, which is discussed by the band bending and the lattice effect due to the Ni dopant. This work paves the way for better controlling the emerging properties of complex oxide heterointerfaces and would be helpful for photoelectric device applications based on all-oxides.

Magnetic Conductive Outer Layer in Oxygen‐Deficient TiO2 Single Crystals

“…The Hall electron mobility rises at different rates upon cooling (see Figure (f)), although they presents nearly similar values at high temperature. Remarkably, the mobility reaches to 16 cm 2 V −1 s −1 at 20 K for the sample with annealing for 3 h, which is approximately similar with the typical mobility of LaAlO 3 /SrTiO 3 interface at low temperatures …”

Metallic conduction and ferromagnetism in MAl2O4/SrTiO3 spinel/perovskite heterostructures (M = Fe, Co, Ni)

“…The metallic interface between two insulating oxides, where a quasi-two-dimensional electron gas (q-2DEG) resides, provides a promising platform for the exploration of emergent phenomena. 1,2 Its attractive physical properties, such as superconductivity, 3 ferromagnetism, 4 high electron mobility, 5 strong gating field, 6,7 quantum Hall effect, 8 and photo excitation effect, 9,10 have drawn extensive interest. So far, the isostructural perovskite-type interface, particularly LaAlO3/SrTiO3 (LAO/STO) 1 has been investigated intensively.…”

Ionic Modulation of Interfacial Magnetism in Light Metal/Ferromagnetic Insulator Layered Nanostructures

“…This effect can be explained as: the thermal distribution under low temperature is much lower and the ME effect is thereby enhanced relatively. This phenomenon also appears in other multiferroics systems like Ni‐doped LaAlO 3 /SrTiO 3 , perpendicular magnetic anisotropy (PMA) structures, etc. As mentioned above, the voltage we applied on the Au electrode was positive and that on the Pt/Cu is negative.…”