Stray-field effects in submicronYBa2Cu3O7−xbicrystal grain boundary junctions

Abstract

We have investigated the magnetic field dependence of the critical current in submicron YBa 2 Cu 3 O 7−x ͓001͔ tilt bicrystal grain boundary junctions. The good homogeneity of submicron grain boundary barrier interfaces, together with the large magnetic field needed to modulate the Josephson current, allow to observe several features not observed in micron size junctions, like a nonconstant modulation period, strongly dependent on the maximum applied magnetic field. Experimental results are well accounted for by a theoretical model taking into account the magnetization of the nearby electrode, and the strong interaction of its stray field with the junction interface. The analysis of the nature of this interaction and the influence of the device geometry are also relevant for potential applications of high critical temperature LSI devices.

Anisotropic distributions of electrical currents in high-T c grain-boundary junctions

“…Among a variety of possible crystallographic orienta tions of grains forming a boundary, the [001] tilt GB (see Fig. 1a) had been studied the most intensively with an emphases on the effect of order parameter symmetry and the mechanisms of charge transfer across the GB interface [1,2,[7][8][9][10][11][12][13][14][15].…”

“…Among a variety of possible crystallographic orienta tions of grains forming a boundary, the [001] tilt GB (see Fig. 1a) had been studied the most intensively with an emphases on the effect of order parameter symmetry and the mechanisms of charge transfer across the GB interface [1,2,[7][8][9][10][11][12][13][14][15].Recently, [100] tilt high T c GB junctions with mutually tilted c axis's (see Fig. 1b) have been fabri cated [16][17][18][19][20][21][22][23][24][25] with an order of magnitude lower GB meandering and up to a threefold increase of the I c R n values [16][17][18][19].…”