An effective approach to achieving low supersaturation for a/b-axis oriented YBa(2)Cu(3)O(7-δ) film growth

Using liquid phase epitaxy, a novel approach was developed to grow a-axis oriented YBa2Cu3O7-δ films (a-films) under an air atmosphere, which has been difficult previously since its formation requires extremely low supersaturation. In our new method, instead of conventional cooling from the saturated to supersaturated state, an extremely small driving force for film growth was generated from the unsaturated through saturated to supersaturated state. By controlling the amount of fresh solvent and the melting time before cooling down the Y-Ba-Cu-O solution, a growth region width up to 30 K was acquired for preparing a-films. Significantly, this work provides a low-cost and convenient way to produce high-quality a-films, which are potentially suitable for Josephson junction devices.