Reversibly switchable electromagnetic device with leakage-free electrolyte

TL;DR

This paper introduces a reversible electromagnetic device that switches the electrical and magnetic properties of transition-metal oxides at room temperature using a novel leakage-free electrolyte, enabling practical applications without leakage issues.

Contribution

The study presents a new leakage-free electrolyte enabling reversible switching of transition-metal oxides, overcoming previous leakage problems in electrochemical devices.

Findings

Reversible switching between insulator/non-magnet and metal/magnet states at 275 K.

Switching achieved within 2-3 seconds under ±3 V DC voltage.

Device operates without liquid leakage, enhancing practicality.

Abstract

Electrical control of oxygen off-stoichiometry of transition-metal oxides at room temperature is a desired strategy to simultaneously switch the electrical conductance and magnetism of the device. Although the use of the electrochemical redox reaction of transition-metal oxides is the most reasonable way to achieve the aforementioned switch, such a device has not been realized because of the lack of a leakage-free liquid electrolyte. Here, we demonstrate an electromagnetic device that can reversibly switch a transition-metal oxide from an insulator/non-magnet to a metal/magnet (Tc=275 K) using a newly developed 'leakage-free electrolyte', incorporated in an amorphous NaTaO3 nanopillar array film. Reversible switching occurs electrically, obeying Faraday's laws of electrolysis, under a DC voltage of +(-)3 V within 2-3 s at RT. The present electromagnetic device does not have the drawback of liquid leakage, and the leakage-free electrolyte provides a novel design concept for practical electromagnetic devices using transition-metal oxides.