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Self-organized current transport through low angle grain boundaries in YBa$_2$Cu$_3$O$_{7-δ}$ thin films, studied magnetometrically

J. R. Thompson·H. J. Kim·C. Cantoni·D. K. Christen·R. Feenstra·D. T. Verebelyi
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Abstract

The critical current density flowing across low angle grain boundaries in YBa$_2$Cu$_3$O$_{7-δ}$ thin films has been studied magnetometrically. Films (200 nm thickness) were deposited on SrTiO$_3$ bicrystal substrates containing a single [001] tilt boundary, with angles of 2, 3, 5, and 7 degrees, and the films were patterned into rings. Their magnetic moments were measured in applied magnetic fields up to 30 kOe at temperatures of 5 - 95 K; current densities of rings with or without grain boundaries were obtained from a modified critical state model. For rings containing 5 and 7 degree boundaries, the magnetic response depends strongly on the field history, which arises in large part from self-field effects acting on the grain boundary.

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J. R. Thompson, H. J. Kim, C. Cantoni, D. K. Christen, R. Feenstra, D. T. Verebelyi. 2003-08-16. Self-organized current transport through low angle grain boundaries in YBa$_2$Cu$_3$O$_{7-δ}$ thin films, studied magnetometrically. https://doi.org/10.1103/physrevb.69.104509

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