Solid-State Electrochemical Protonation of SrCoO_2.5 into H_<i>x</i>SrCoO_2.5 (<i>x</i> = 1, 1.5, and 2)

Among many transition-metal oxides (TMOs), strontium cobalt oxide (SrCoOx) is a promising active material for advanced memory devices due to the versatile valence state of ions. Several SrCoOx-based electrochemical have been proposed, but solid-state protonation from SrCoO2.5 HxSrCoO2.5 (x = 1, 1.5, and 2) at room temperature has not demonstrated thus far absence an appropriate solid electrolyte. Here, we demonstrate using mesoporous amorphous 12CaO·7Al2O3 (CAN) film as The crystalline phase discretely changed HSrCoO2.5 (phase A), H1.5SrCoO2.5 B), H2SrCoO2.5 C) through formation intermediate H1.25SrCoO2.5. B) was colorless transparent showed weak ferromagnetism. present results indicate that CAN can be used electrolyte treatment TMOs.