Transport Properties And Electronic Phase Diagram Of Single-Crystalline Ca-10(Pt3as8)((Fe1-Xptx)(2)As-2)(5)

Sizable single-crystalline samples of Ca-10(Pt3As8)((Fe1-xPtx)(2)As-2)(5) (the 10-3-8 phase) with 0 <= x < 0.1 have been grown and have been systematically characterized via x-ray diffraction, magnetic, and transport measurements. The unsubstituted sample is a heavily doped semiconductor with no sign of magnetic order down to 2 K. With increasing Pt content, the metallic behavior appears, and superconductivity is realized for x >= 0.023. T-c rises to its maximum of approximately 13.6 K at the doping level of x similar to 0.06 and then decreases for higher x values. The electronic phase diagram of the 10-3-8 phase was mapped out based on the magnetic and transport measurements. The mass anisotropy parameter Gamma similar to 10, obtained from resistive measurements in magnetic fields, indicates a relatively large anisotropy in the iron-based superconductor family. This strong two-dimensional character may lead to the absence of magnetic order. A linear T dependence of susceptibility at high temperatures is observed, indicating that spin fluctuations exist in the underdoped region as in most of the Fe-pnictide superconductors.