Sizable single-crystalline samples of ${\mathrm{Ca}}_{10}\left({\mathrm{Pt}}_3{\mathrm{As}}_8\right){\left({\left({\mathrm{Fe}}_{1-x}{\mathrm{Pt}}_x\right)}_2{\mathrm{As}}_2\right)}_5$ (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 $x⩾0.023$. $T_{\mathrm{c}}$ rises to its maximum of approximately 13.6 K at the doping level of $x\sim 0.06$ 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 $\Gamma \sim 10$, 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.

• Received 8 March 2012

DOI:https://doi.org/10.1103/PhysRevB.85.224527