Electrical Resistivity of Iodine-Intercalated Bi2Sr2CaCu2O8 Subjected to a Magnetic Field

Abstract

In this work we report on the intercalation of single crystals of Bi2Sr2CaCu2O8 with iodine to form the stage-1 intercalated complex IBi2Sr2CaCu2O8, and on the electrical resistivity of this final product, both as a function of temperature, T, (between 10 K and 300 K) and magnetic field, H, (going up to 15 T). Both ρ ab , the resistivity in the ab-plane, and ρ c , the resistivity along the c-axis have been studied for H // ab and H // c. We find that the metallic character of electrical conduction along the c-axis observed in the normal state in intercalated samples (as compared with the semiconducting character in the pristine host) is maintained when a magnetic field is applied, confirming that, in the normal state, a reduction in the anisotropy accompanies the intercalation process. In the superconducting state, however, we find that the magnetic field causes a broadening of the superconducting transition (as in non-intercalated Bi2Sr2CaCu2O8), especially when H // c, indicating that the superconducting state retains a highly anisotropic character after intercalation. The resistivity data in the flux-flow regime have also allowed us to estimate values of the activation energy for vortex movement.