Anisotropy of iron-platinum-arsenide Ca10(PtnAs8)(Fe2-xPtxAs2)5 single crystals

TL;DR

This study investigates the anisotropy of the upper critical field in Ca10(PtnAs8)(Fe2-xPtxAs2)5 single crystals, revealing high anisotropy levels and a linear relationship with interlayer distance, providing insights into the superconducting properties of iron-based superconductors.

Contribution

It provides the first detailed analysis of Hc2 anisotropy in these specific Ca10-based crystals and establishes a correlation between anisotropy and interlayer distance in iron-based superconductors.

Findings

Anisotropy parameter γ reaches about 10 at 0.8Tc.

γ increases linearly with FeAs/FeSe interlayer distance.

FeSCs are less anisotropic than cuprates, indicating weaker two-dimensionality.

Abstract

The upper critical field Hc2 anisotropy of Ca10(PtnAs8)(Fe2-xPtxAs2)5 (n = 3, 4) single crystals with long FeAs interlayer distance (d) was studied by angular dependent resistivity measurements. A scaling of the angular dependent resistivity was realized for both single crystals using the anisotropic Ginzburg-Landau (AGL) approach with an appropriate anisotropy parameter {\gamma}. The AGL scaling parameter {\gamma} increases with decreasing temperature and reaches a value of about 10 at 0.8Tc for both single crystals. These values are much larger than those of other iron-based superconductors (FeSCs). Remarkably, the values of {\gamma}2 show an almost linear increase with the FeAs/FeSe interlayer distance d for FeSCs. Compared to cuprates, FeSCs are less anisotropic, indicating that two dimensionality of the superconductivity is intrinsically weak.