Resistor network model for simulation of current and flux percolation in granular coated conductors

A computer model has been developed to simulate Current percolation and dissipation in coated conductors. Experimentally measured grain morphologies as well as model geometries were studied. It was assumed that the dissipation is generated entirely at grain boundaries (GB's) by viscous flux flow. Therefore, each GB had a piecewise linear current-voltage (I-V) characteristic. The current distribution and flux penetration were calculated using standard methods of linear optimisation. I-V characteristics and critical currents were calculated as function of various processing and electromagnetic parameters. The I-V curves showed a power-law scaling which is typical for percolative processes. (C) 2002 Elsevier Science B.V. All rights reserved.