Reversible phase switching between antiferromagnetic SrCoO2.5 and ferromagnetic SrCoO3−δ by a flexible solid-state electrolyte gate

Abstract Manipulation of oxygen vacancies (VO) in transition metal oxides (TMOs) can largely alter their physical and chemical properties, such as electrical conductivity, magnetic state, optical band-gap, and electrocatalytic reactivity. Many experimental and theoretical works have been conducted to study the formation/annihilation of VO and its corresponding effect on the properties in TMOs. In this paper, a solid-state approach to modulate the oxygen stoichiometry in high quality SrCoOx epitaxial thin films was demonstrated. Dependence of the magnetic and electrical conducting properties on VO was investigated. Room temperature reversible phase switching between brownmillerite antiferromagnetic insulating SrCoO2.5 and perovskite ferromagnetic metallic SrCoO3-δ was achieved by electric-field induced oxygen non-stoichiometry. This room temperature reversible phase switching indicates that SrCoOx thin films are a promising candidate for practical applications in resistive random access memory and spintronic devices.