Long-range current flow and percolation in RABiTS-type conductors and the relative importance of out-of-plane and in-plane misorientations in determining Jc

Calculations of long-range current flow using an advanced percolation model show that with the presently observed texture in RABiTS substrates, the dependence of J(c) on length as a function of width is greatly reduced. Furthermore, this dependence becomes almost negligible in applied fields. These results suggest that sub-division of a wide conductor into narrow filaments should be possible without loss in J(c). The relative importance of the out-of-plane texture in affecting intergranular J(c) was also explored by fabricating RABiTS substrates with different out-of-plane textures but approximately the same in-plane texture. This was accomplished by using TiN as a seed layer for which significant sharpening of the out-of-plane texture is observed. Similar J(c) was found for samples with differing out-of-plane texture but almost the same in-plane texture. Finally, separation of the total misorientation in GB networks into in-plane and out-of-plane misorientations using manipulations in Rodrigues space shows that J(c) correlates best with in-plane texture. (c) 2005 Elsevier B.V. All rights reserved.