Pressure cycle of superconducting Cs0.8Fe2Se2 : A transport study

G. SEYFARTH; D. JACCARD; P. PEDRAZZINI; A. KRZTON-MAZIOPA; E. POMJAKUSHINA; K. CONDER; Z. SHERMADINI

SOLID STATE COMMUNICATIONS

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2011 vol. 151 p. 747 - 750

0038-1098

We report measurements of the temperature and pressure dependence of the electrical resistivity (ρ) of single-crystalline iron-based chalcogenide Cs0.8Fe2Se2. In this material, superconductivity with a transition temperature (Tc ) ∼ 30 K develops from a normal state with extremely large resistivity. At ambient pressure, a large ‘‘hump’’ in the resistivity is observed around 200 K. Under pressure, the resistivity decreases by two orders of magnitude, concomitant with a sudden Tc suppression around pc ∼ 8 GPa. Even at 9 GPa a metallic resistivity state is not recovered, and the ρ(T ) ‘‘hump’’ is still detected. A comparison of the data measured upon increasing and decreasing the external pressure leads us to suggest that the superconductivity is not related to this hump.