Voltage-Controlled Oxygen Non-Stoichiometry in SrCoO3−δ Thin Films

Oxygen nonstoichiometry plays a critical role in determining the physical and chemical functionalities of oxide materials. For widespread applications involving oxygen transport and exchange with the environment, fast, inexpensive, and reversible control of oxygen deficiency is highly desired. This article illustrates voltage-controlled oxygen nonstoichiometry in SrCoO 3−δ (SCO) thin films, in which the oxygen deficiency (δ) can be tuned between 0 and 0.5 within tens of seconds by a small applied voltage (<1.7 V). Correspondingly, its magnetism as well as the electrical and optical properties can be tuned accordingly from one end to the other, making it a good candidate for a number of commercial applications, such as oxygen capacitors, catalysts, smart windows, and so forth. This approach can be used as an effective method in imaging the phase diagrams of transition-metal oxides, such as ternary ABO 3−δ (A = Ln, Ca, Sr, Bi; B = Cr, Mn, Co, Fe, Ni) or binary TiO x, WO x, VO x and NiO x, and so forth, paving the way for the search for novel properties in redox materials.