上海科技大学知识管理系统

For high-critical-temperature (high-T-c) superconductors, the normal state transport properties at low temperatures are of great importance to understand the Fermi surface structure and carrier profile. In this work we studied the doped ultrathin Ba0.57K0.43Fe2As2 system, a member of the optimally doped 122-type multigapped iron-based superconductors with complex superconducting gap structure. To explore the normal state resistivity below the zero-field superconducting T-c, both Co and Zn dopants were substituted into the superconducting Fe2As2 layer to suppress the superconductivity. The temperature dependence of in-plane resistivity below T-c reveals a typical metallic behavior with the magnetic fields up to 45 T along c axis. A linear dependence of Hall resistivity (rho(xy)) is observed for Ba0.57K0.43Fe2As2 and Ba0.57K0.43(Fe0.96Zn0.04)(2)As-2 at high magnetic field, indicating a conventional metal profile. Nevertheless, the Co dopants lead to a decreasing d rho(xy)/dH when the field is above 20 T. Such transformation of carrier transport properties may be contributed by band shift within a two-carrier model.