Interfacial control of oxygen vacancy doping and electrical conduction in thin film oxide heterostructures

Abstract

Oxygen vacancies in proximity to surfaces and heterointerfaces in oxide thin film heterostructures have major effects on properties, resulting, for example, in emergent conduction behaviour, large changes in metal-insulator transition temperatures or enhanced catalytic activity. Here we report the discovery of a means of reversibly controlling the oxygen vacancy concentration and distribution in oxide heterostructures consisting of electronically conducting In2O3 films grown on ionically conducting Y2O3-stabilized ZrO2 substrates. Oxygen ion redistribution across the heterointerface is induced using an applied electric field oriented in the plane of the interface, resulting in controlled oxygen vacancy (and hence electron) doping of the film and possible orders-of-magnitude enhancement of the film's electrical conduction. The reversible modified behaviour is dependent on interface properties and is attained without cation doping or changes in the gas environment.

Transformation of oxide ceramic textiles from insulation to conduction at room temperature

“…On the other hand, the conductivity of oxides greatly relies on their surface oxygen defects (14)(15)(16)(17). Tremendous efforts have been focused on high-temperature reduction to create defects (18)(19)(20)(21)(22)(23)(24).…”

High-temperature superconductivity at the lanthanum cuprate/lanthanum–strontium nickelate interface

“…[17][18][19] Such effects, which are typically confined within a few nanometers across an interface and which do not belong to the single constituting phases, have been ascribed to different phenomena comprising inter alia epitaxial strain, 20,21 electronic charge transfer 22 and cationic and anionic local nonstoichiometry. [23][24][25][26] In this context, we present here a comprehensive study of the structural and functional properties of heterostructures composed of lanthanum cuprate (La 2 CuO 4 -LCO) and Sr-doped lanthanum nickelate (La 2−x Sr x NiO 4 -LSNO), fabricated by atomic-layer-by-layer molecular beam epitaxy (ALL-MBE), 27 and we demonstrate that high-temperature superconductivity (superconducting critical temperature T c up to ≈40 K) can be induced in LCO at the contact with LSNO, even though neither of the two phases alone exhibit superconductivity per se.…”

Effects of oxygen vacancies on the electronic structure of the (LaVO3)6/SrVO3 superlattice: a computational study

“…O vacancies in transition metal oxides are becoming increasingly critical in device applications, since they act as electron donors and therefore can strongly perturb the electronic structure [1][2][3]. On the other hand, as the O vacancy concentration may be reversibly controlled by an external electric field or by epitaxial strain, the electronic conductivity and magnetism of transition metal oxides can be tuned without introducing other impurities [4,5]. Numerous experimental and theoretical works have investigated the formation and diffusion of O vacancies (and the induced effects on the electronic and magnetic properties) in transition metal oxide thin films [5][6][7][8] and heterostructures [9][10][11], while the role of O vacancies in superlattices is still a developing field.…”