Metallic and Insulating Interfaces of Amorphous SrTiO₃-Based Oxide Heterostructures

Abstract

The conductance confined at the interface of complex oxide heterostructures provides new opportunities to explore nanoelectronic as well as nanoionic devices. Herein we show that metallic interfaces can be realized in SrTiO 3 -based heterostructures with various insulating overlayers of amorphous LaAlO 3 , SrTiO 3 and yttria-stabilized zirconia films. On the other hand, samples of amorphous La 7/8 Sr 1/8 MnO 3 films on SrTiO 3 substrates remain insulating. The interfacial conductivity results from the formation of oxygen vacancies near the interface, suggesting that the redox reactions on the surface of SrTiO 3 substrates play an important role.

Electronic Reconstruction at the Interface Between Band Insulating Oxides: The LaAlO3/SrTiO3 System

“…Thus alternative models should explain why the q2DES appears only at a critical thickness. This is quite important, since this feature clearly distinguishes the mechanism of formation of a conducting system in epitaxial LAO/STO from the recent reports of conductivity at amorphous/STO interfaces [52]. For amorphous/STO interfaces there is no clear critical thickness and the interfaces become insulating after annealing in O 2 , so that for these systems oxygen vacancies are the most plausible explanation of the phenomenon [53].…”

Nonvolatile Resistive Switching inPt/LaAlO3/SrTiO3Heterostructures

“…This mechanism, along with the polar distortion and dipole screening in the LAO overlayers [16], can qualitatively explain the transport properties. In addition, factors like oxygen vacancies [17][18][19] and cation mixing [20][21][22] may influence the characteristics of the electron gas [23][24][25][26][27].…”

Unraveling the enhanced Oxygen Vacancy Formation in Complex Oxides during Annealing and Growth

“…have recently found that an increased ion bombardment via the laser plume results in an increased reduction10. Another explanation often found in literature is the oxidization of the growing thin film by the STO substrate, eventually resulting in the reduction of the substrate293031. However, as soon as the plume is turned off one would expect the oxygen content of the sample to approach the equilibrium value and thus to reoxidize at a certain rate within the PLD chamber21.…”