Integrated multilayer sputter-induced 45° YBa2Cu3O7−x grain boundary junctions

Abstract

A versatile multilayer technique has been developed to form 45° YBa2Cu3O7−x [001] tilt grain boundary junctions on LaAlO3 substrates. An epitaxial MgO layer is initially deposited on a (100) LaAlO3substrate using pulsed organometallic beam epitaxy (POMBE). After a pregrowth sputter treatment, an YBa2Cu3O7−x thin film is then grown using POMBE. The resultant film is c-axis oriented with a cube-on-cube orientation over the unsputtered portion of the MgO, and rotated by 45° about the [001] axis on the sputtered region of the substrate. The resulting grain boundary junction shows weak-link behavior. The advantage of this technique is the ability to place the grain boundary anywhere on the substrate in any configuration, and the potential to use any substrate upon which MgO can be epitaxially grown.