Superconductivity in SmFeAsO_(0.8)F_(0.2) Synthesized by High Pressure High Temperature Treatment

摘要

Superconducting SmFeAsO_(0.8)F_(0.2) compound was successfully synthesized by high pressure high temperature treatment with pressure of 6 G Pa at 1400 °C for 2 hours. The X-ray diffraction pattern of the sample indicates the formation of the tetragonal ZrCuSiAs-type SmFeAsO_(0.8)F_(0.2) with lattice parameters a=3.932 A and c=8.490 A. The electrical transport study shows that the sample has a rather high transition temperature Tc of about 52 K, and magnetic field effect on the resistance reveals a rather high upper critical field H_(C2) of about 65 T.