The role of ionic liquids in the synthesis of the high-temperature superconductor YBa₂Cu₃O_7-δ

The ionic liquid method has proved to be an interesting tool in the synthesis of metal oxides. There is a lack of understand-ing however of how these materials interact with and which factors can be beneficial or detrimental for, the synthesis of a pure phase metal oxide. Here we present an extensive mechanistic study of the synthesis of the high temperature supercon-ductor YBa₂Cu₃O_7-δ (YBCO) using different ionic liquids and deep eutectic solvents such as 1-ethyl-3-methylimidazolium acetate (emim)OAc, ethylene glycol:choline chloride and imidazole:choline chloride, as well as mono-molecular chelating agents, namely ethylene glycol and imidazole. All the reactions were supported using dextran as a non-specific, polychelating agent.