A multi-layer technique was used to form 45 Cu3Ba2YO7-x [001] tilt grain-boundary junctions on LaAlO3 substrates. An epitaxial MgO layer was initially deposited onto the (100) substrate by using pulsed organometallic beam epitaxy. After a pre-growth sputtering treatment, a Cu3Ba2YO7-x thin film was then grown by using pulsed organometallic beam epitaxy. The resultant film was c-axis oriented, with a cube-on-cube orientation, over the unsputtered portion of the MgO and was rotated by 45 about the [001] axis on the sputtered region of the substrate. The resultant grain-boundary junction exhibited weak-link behavior. The advantage of this technique was the possibility of locating the grain boundary anywhere on the substrate (and in any configuration), and of using any substrate upon which MgO could be epitaxially grown.

B.V.Vuchic, K.L.Merkle, K.A.Dean, D.B.Buchholz, R.P.H.Chang, L.D.Marks: Applied Physics Letters, 1995, 67[7], 1013-5