Superconductivity at 32 K and anisotropy in Tl0.58Rb0.42Fe1.72Se2 crystals
Department of Physics, Zhejiang University - Hangzhou 310027, China
2 Department of Physics, Hangzhou Normal University - Hangzhou 310036, China
Accepted: 2 February 2011
Tl0.58Rb0.42Fe1.72Se2 single crystals were successfully synthesized with the Bridgeman method. The physical properties are characterized by electrical resistivity, magnetization and Hall resistivity. Tl0.58Rb0.42Fe1.72Se2 undergoes a superconducting transition at Tconset=32 K and Tczero=31.4 K. Extrapolation of the upper critical field Hc2 at Tc to zero temperature gives a large value of Hc2(0) (Hc2(0)=221 T for H||ab and Hc2(0)=44.2 T for H||c). The Hall coefficient changes sign upon cooling down, indicating a possible multi-band behavior. The normal-state magnetic susceptibility decreases with decreasing temperature, suggesting strong antiferromagnetic (AFM) spin fluctuations, which might be related to the superconductivity (SC).
PACS: 74.62.Bf – Effects of material synthesis, crystal structure, and chemical composition / 74.25.F- – Transport properties / 74.25.Ha – Magnetic properties including vortex structures and related phenomena
© EPLA, 2011