Preparation of High-Tc A-Axis Oriented EBCO Thin Films on R-Sapphires with CeO2\PBCO Buffer Layers Using dc Magnetron Sputtering

We attempted to deposit a-axis oriented EuBa2Cu3O7-δ(EBCO) with T ce’s above 85 K on Al2O3(1102) substrates with CeO2(001) buffer layers by introducing a template layer of PrBa2Cu3O x (PBCO). Growth conditions of substrate temperature (T s) and deposition rate (R d) for a-axis oriented PBCO layers were estimated. The PBCO films were prepared at a T s of 620°C and a Rd of 35 A/ min on the CeO2 buffer layers. The maximum substrate temperature where a-axis oriented EBCO films grew on the a-axis oriented PBCO layers of thicknesses above 700 A was about 30°C higher than that on CeO2(001) layers. The EBCO films with a- and b-axis orientation were deposited on R-sapphire\CeO2(001) substrates with a-axis oriented 1000-A-thick PBCO template layers at a T s of 650°C and exhibited T ce’s of about 86.7 K.