An article including a substrate, at least one intermediate layer upon the
surface of the substrate, a layer of an oriented cubic oxide material
having a rock-salt-like structure upon the at least one intermediate
layer, and a layer of a SrRuO.sub.3 buffer material upon the oriented
cubic oxide material layer is provided together with additional layers
such as a HTS top-layer of YBCO directly upon the layer of a SrRuO.sub.3
buffer material layer. With a HTS top-layer of YBCO upon at least one
layer of the SrRuO.sub.3 buffer material in such an article, J.sub.c 's of
up to 1.3.times.10.sup.6 A/cm.sup.2 have been demonstrated with projected
I.sub.c 's of over 200 Amperes across a sample 1 cm wide.
