Tailoring the Superconductivity and Antiferromagnetic Order in SrFe2-xRhxAs2

By doping Rh to the Fe sites in SrFe2As2, superconductivity is induced when the antiferromagnetic (AF) order is suppressed. The maximum superconducting transition temperature was found at about 22 K with the doping level of x = 0.25. It is found that the resistivity anomaly associating with the AF order reveals a sharp drop for the parent phase and the samples with low doping (x = 0.05), while it evolves into an uprising at a higher doping level (x = 0.1). A general phase diagram is depicted which exhibits the similarity with that of Co doping. Regarding the close maximum superconducting transition temperatures in doping Co, Rh and Ir, we argue that the superconductivity is intimately related to the suppression of the AF order, rather than the electron-phonon coupling.