Nonrandom percolation behavior of grain boundary networks in high-T[sub c] superconductors

Frary, M.; Schuha, C. A.
November 2003
Applied Physics Letters;11/3/2003, Vol. 83 Issue 18, p3755
Academic Journal
The grain boundary networks of tetragonal and orthorhombic superconductors are shown to be nonrandom through computer simulations of polycrystalline structures. For biaxially textured microstructures, the distribution of low-angle grain boundaries around triple junctions is measurably deviant from the expectations for a randomly constructed lattice. Percolation thresholds are calculated for the unhindered flow of superconducting current through a polycrystal, and are found to be significantly different from the standard random percolation threshold in two dimensions. These deviations are explained as a result of crystallographic constraints on the network topology. © 2003 American Institute of Physics.


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