Suppression of superconductivity in Zn-doped SmFeAsO0.8F0.2 system

Abstract: A series of SmFe1− x Zn x AsO0.8F0.2 samples with x =0, 0.05, 0.1, 0.2 and 0.4 have been successfully synthesized using a solid state method. The lattice parameters are found to increase with increasing Zn doping content. The superconductivity has been definitely suppressed by Zn doping at Fe site with the transition temperature T c being reduced from 52.5K to 23.3K for the sample of x =0.05, and to 18.2K for the sample of x =0.1. For the samples with x >0.1, the superconducting transition vanishes, and, at the meantime, the spin-density-wave anomaly recovers at 140K. The metal to semiconductor transition is also observed in the SmFe1− x Zn x AsO0.8F0.2 system. The behavior of SmFe1− x Zn x AsO0.8F0.2 is very different from that of REFeAsO (RE =rare earth metal), which reveals a very strong electron correlation in SmFe1− x Zn x AsO0.8F0.2. [Copyright &y& Elsevier]