Changes of the dimensionality and Tc through the iodine intercalation and oxidation in Bi2Sr2CaCu2O8+δ single crystals

The effects of stage-one iodine intercalation and oxidation on the dimensionality of the physical properties and on the superconducting transition temperature Tc have been investigated in Bi2Sr2CaCu2O8+δ single crystals. Both intercalation and oxidation change the dimensionality of the normal-state properties from pseudo-two-dimensional to three-dimensional, decrease Tc and also change the magnetic-field dependence of the activation energy in the flux creep. The broadening of the resistive superconducting-transition under magnetic fields is suppressed through only the oxidation. These changes through the intercalation and oxidation have been found to be explained by the multilayer model, where a high-Tc superconductor is regarded as an alternating stack of the CuO2 layer (S layer) and the block layer (N layer), taking account of the proximity effect and of the redistribution of carriers to the S and N layers. We have arrived at the conclusion that the multilayer model can be one of the candidates for the model of high-Tc superconductors.