Preparation of bi-axially aligned YBa₂Cu₃O_7-δ film on CeO₂-buffered MgO by chemical solution deposition

We have succeeded in preparing in-plane aligned YBa₂Cu₃O_7-δ (Y123) film by chemical solution deposition (CSD) processing on CeO₂ (100)-buffered MgO (100) substrates. The CeO₂ buffer film was deposited on MgO (100) single crystalline substrate by pulsed laser deposition (PLD). For CSD coating, a homogeneous coating solution having a molar ratio of Y:Ba:Cu = 1:2:3, was prepared by dissolving metal naphthenates in toluene. This solution was spin-coated both on the YSZ (100) and on the CeO₂-buffered MgO (100) single crystalline substrates. The precursor films were calcined at 425 °C and fired at various temperatures under low oxygen partial pressure (pO₂). All Y123 films showed strong (00n) peaks, which correspond to c-axis orientation perpendicular to the substrates and their a/b-axes were in-plane aligned. We confirmed that CeO₂ buffer is usable for CSD processing. While the Y123 films on the YSZ reacted with the substrate forming BaZrO₃ phase and did not show sufficient superconducting properties. The T_c,zero value of the Y123 film prepared on CeO₂-buffered MgO substrate was 91.5 K and J_c was 1.2x×10⁵ A/cm² at 77 K, 0 T.