Bi-epitaxial template grain boundaries with different in-plane angles on (100) MgO substrates

Abstract

Using laser ablation CeO 2 and YBa2Cu307. d layers have been deposited on (100) oriented MgO substrates for the creation of bi-epitaxial grain boundary weak links. X-Ray Diffraction measurements were used to measure the (in-plane) orientations of the layers. The CeO 2 layer has been structured using Ar ion beam etching or CaO lift off. Using these two structuring techniques it is possible to obtain two different grain boundary weak link angles: 18 and 27 degrees. Up till now only 45 degrees weak link angles have been reported in literature, using templates for the creation of these grain boundaries.

Grain boundaries in high-Tcsuperconductors

“…II), one might expect that grain-boundary angles other than 45°are also obtainable in [001]-oriented YBa 2 Cu 3 O 7Ϫ␦ films by using the biepitaxial template process. Indeed, some exceptions from a cube-to-cube or a 45°-rotated growth have been reported, e.g., an inplane rotation of 18°occurring for CeO 2 films grown on MgO substrates (Ijsselsteijn et al, 1993), and in-plane rotations of 9°for YBa 2 Cu 3 O 7Ϫ␦ grown on YSZ (Schlom et al, 1996). To date, however, no process has been established to create reproducible [001]-tilt boundaries with angles deviating from 45°.…”

“…1 See, for example, Ijsselsteijn et al, 1993Ijsselsteijn et al, , 1994Vollnhals et al, 1994;Li et al, 1995;Petersen, Stolzel, et al, 1995;Boikov et al, 1997aBoikov et al, , 1997bY. Chen et al, 1997;Horng et al, 1997;Villegier, 1997a, 1997b;Tsaiet al, 1998.…”

The mechanism of sputter-induced epitaxy modification in YBCO (001) films grown on MgO (001) substrates

“…Many methods have been developed to fabricate grain boundary junctions (GBJ's). Among others, the step edge method, 1,2 bicrystal method, [3][4][5] and biepitaxy method 6,7 have been extensively studied. Junctions made by the bicrystal method are presently being used in commercial devices.…”