Engineering of YBa₂Cu₃O_7–δ grain boundary Josephson junctions by Au nanocrystals

Abstract We prepared and investigated grain boundary Josephson junctions based on SrTiO₃ bicrystal substrates. During the deposition of YBa₂Cu₃O_7–δ (YBCO) gold nanocrystals forming from an intermediate gold layer can modify the crystalline structure and thus the properties of the YBCO grain boundaries. The variation of the film thickness of the Au seed layer changes the growth conditions of the YBCO film and the Au nanocrystals. The values of the characteristic I_CR_N product do not change whereas the values of the critical current I_C decrease. magnified image (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)