ac resistivity of d-wave ceramic superconductors

We model d-wave ceramic superconductors with a three-dimensional lattice of randomly distributed pi Josephson junctions with finite self-inductance. T he linear and nonlinear ac resistivity of the d-wave ceramic superconductor s is obtained as a function of temperature by solving the corresponding Lan gevin dynamical equations. We find that the linear ac resistivity remains f inite at temperature T-p where the third harmonics of resistivity has a pea k. The current amplitude dependence of the nonlinear resistivity at the pea k position is found to be a power law. These results agree qualitatively wi th experiments. We also show that the peak of the nonlinear resistivity is related to the onset of the paramagnetic Meissner effect which occurs at th e crossover temperature T-p, which is above the chiral glass transition tem perature T-cg.