Growth of Double Perovskite A₂BB’O₆ Single Crystals in various Fluxes

Double perovskites of the form A₂BB’O₆, which mimic a rock-salt type structure with BO₆ and B’O₆ octahedra, are rapidly emerging materials due to their versatility and possible applications in multiferroics, photovoltaics, spintronics, to name a few. Single crystals of double perovskites have been produced by the flux growth method. Flux synthesis is an extremely advantageous and widely applied growth method to produce high-quality single crystals while controlling the temperature and rates of heating and cooling. Growth of single-crystalline double perovskites was attempted with two methods: solid state synthesis using oxides which was subsequently used as precursors in a molten flux to form single crystals, and oxides directly in a molten flux without prior solid state synthesis. Major considerations include the reaction vessel, the growth environment (air/vacuum/argon), interaction between cations and chosen flux, temperature, dwell time, and heating and cooling rates. Attempts, challenges, and potential directions are discussed.