Superconducting glass behavior and frustration in polycrystalline Sm2−xCexCuO4−y

Abstract A magnetic field was used to separate contributions to superconductivity from islands and inter-island Josephson coupling in polycrystalline samples of Sm 2− x Ce x CuO 4− y (0.14≤x≤0.17). The electrical resistivity below the Josephson coupling temperature T cJ is significantly larger in the zero-field-cooled state than in the field-cooled state up to 1 kOe, implying metastable configurations. As the field is increased, T cJ decreases rapidly up to 1 kOe and saturates at higher fields. These observations indicate a glass state in a disordered Josephson array.