open access

https://hdl.handle.net/2115/85830

Solid-state electrochemical redox control of the optoelectronic properties for SrFeOx thin films

英語

2021-06-07

American Institute of Physics (AIP)

Journal of Applied Physics

129(21)

215303

By utilizing redox reactions, the physical properties of several transition metal oxides can be drastically changed, which is useful for developing multifunctional memory devices. Strontium iron oxide (SrFeOx), which exhibits a clear phase transition from antiferromagnetic insulator (x = 2.5) to helimagnetic metal (x = 3), is a good candidate for the active material in multifunctional memory devices. However, practical applications using previous demonstrations of redox reactions in SrFeOx are limited by the use of a liquid electrolyte due to the leakage problem. Here, we demonstrate solid-state electrochemical redox reaction in SrFeOx using a yttria-stabilized zirconia (YSZ) single-crystal substrate as the solid electrolyte. We fabricated the SrFeO2.5 film on the YSZ substrate and the applied electric current using Au electrodes. The phase gradually changed from SrFeO2.5 to SrFeO2.5+x and SrFeO3-x. The color of the film changed from yellowish-transparent to dark brown. Although the as-grown SrFeO2.5 film showed high resistivity (rho > 10(1) omega cm), the rho dramatically decreased (similar to 10(-2) omega cm) with increasing the applied charge density. Simultaneously, the thermopower greatly decreased from similar to+200 to similar to-10 mu V K-1. The present results would provide a design concept for future SrFeOx-based solid-state multifunctional memory devices.

学術雑誌論文

Version of Record

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in (Qian Yang, Hai Jun Cho, Hyoungjeen Jeen, and Hiromichi Ohta , "Solid-state electrochemical redox control of the optoelectronic properties for SrFeOx thin films", Journal of Applied Physics 129, 215303 (2021) https://doi.org/10.1063/5.0053939) and may be found at (https://doi.org/10.1063/5.0053939).

0021-8979