Electric-field control of oxygen vacancy and magnetic phase transition in cobaltite/manganite bilayer

TL;DR

This paper demonstrates reversible electric-field control of oxygen vacancies and magnetic phase transitions in cobaltite/manganite bilayers, providing new insights into V_O engineering in complex oxide heterostructures.

Contribution

It reveals how electric fields can reversibly manipulate oxygen vacancies and magnetic phases in oxide bilayers, supported by theoretical analysis.

Findings

Reversible magnetic phase transition sequence controlled by electric field

V_O formation/annihilation depends on formation energies and Gibbs free energy

Provides insight into electric field-driven V_O engineering in heterostructures

Abstract

Manipulation of oxygen vacancies (V_O) in single oxide layers by varying the electric field can result in significant modulation of the ground state. However, in many oxide multilayers with strong application potentials, e.g. ferroelectric tunnel junctions and solid-oxide fuel cells, understanding V_O behaviour in various layers under an applied electric field remains a challenge, owing to complex V_O transport between different layers. By sweeping the external voltage, a reversible manipulation of V_O and a corresponding fixed magnetic phase transition sequence in cobaltite/manganite (SrCoO3-x/La0.45Sr0.55MnO3-y) heterostructures are reported. The magnetic phase transition sequence confirms that the priority of electric-field-induced V_O formation/annihilation in the complex bilayer system is mainly determined by the V_O formation energies and Gibbs free energy differences, which is supported by theoretical analysis. We not only realize a reversible manipulation of the magnetic phase transition in an oxide bilayer, but also provide insight into the electric field control of V_O engineering in heterostructures.