Superconducting properties of iron–platinum–arsenides Ca10(PtnAs8)(Fe2−xPtxAs2)5 (n = 3, 4)

• Iron–platinum arsenides Ca10(PtnAs8)(Fe2−xPtxAs2)5 (n = 3, 4) have been grown and characterized.
• Due to modest electromagnetic anisotropy, resistive transition shows broadening.
• Magneto-optical imaging confirm homogeneous superconducting states.
• Proton irradiation into n = 3 compound leads to Tc suppression by ∼2 K and Jc enhancement by a factor of three.

High-quality single crystals of iron–platinum arsenides Ca10(PtnAs8)(Fe2−xPtxAs2)5 (n = 3, 4) have been grown and their superconducting properties are characterized. The n = 4 and n = 3 compounds have Tc’s ∼ 30 K and 13 K, respectively. Reflecting a modest anisotropy of the system, resistive transition for H//c-axis shows modest broadening in both systems. Magneto-optical imaging shows that superconductivity in both compounds is rather homogeneous, with the critical current density, Jc, ∼1 × 105 A/cm2 at 5 K under self-field. Proton irradiation up to 4 × 1016 cm−2 into n = 3 compound is found to have Tc suppression by ∼2 K and Jc enhancement by a factor of three at low temperatures.