Superconducting glassy state in high-T_c oxides

Abstract

Starting with the first observation of a superconducting glassy state in La2-xBaxCuO4 ceramics by susceptibility and magnetic moment measurements, recent microwave absorption experiments as well as magnetic relaxation effects will be presented and discussed in the light of very large scale Monte Carlo computer simulations. The origin of the superconducting glass state is inferred as being due to Josephson junctions or weak links partly internal to the ceramic grains or single crystals occuring at twin boundaries. © 1987.