Pressure-induced shift of Tc in KxSr 1-xFe2As2 (x=0.2,0.4,0.7): Analogy to the high-Tc cuprate superconductors

Abstract

The systematic pressure shifts of Tc were investigated in the whole phase diagram of the FeAs-based superconducting compound K xSr1-xFe2As2. Different regions, arising from corresponding responses of Tc to pressure (dT c/dp>0, ≃0, or <0), can be clearly distinguished. This reveals an interesting similarity of the FeAs superconductors and the high-Tc cuprates. This behavior is a manifestation of the layered structure of the FeAs compounds and the pressure-induced charge transfer between the (Fe2As2) and (K/Sr) layers. The coexistence of superconductivity and spin-density wave behavior were also observed, and the pressure effects on the latter is explored. © 2008 The American Physical Society.