| Abstract: | The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2(As1-ySby)2 system have been studied through electrical resistivity measurements. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-Tc superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤ y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y > 0.06 and the conventional Fermi liquid is restored, while the low-Tc phase remains robust against Sb impurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system. |
