Synthesis and properties of La-doped CaFe2As2 single crystals with Tc = 42.7 K

TL;DR

This study reports the successful synthesis of high-quality La-doped CaFe2As2 single crystals exhibiting superconductivity at 42.7 K, with detailed analysis of their structural and magnetic properties.

Contribution

It introduces a new method for synthesizing La-doped CaFe2As2 crystals with enhanced superconducting transition temperature and characterizes their anisotropic upper critical fields.

Findings

Superconducting transition temperature of 42.7 K achieved.

High crystalline quality confirmed by x-ray diffraction.

Anisotropy of upper critical field approximately 3.3.

Abstract

Large single crystals of La-doped CaFe2As2 were successfully synthesized by the FeAs self-flux method. The x-ray diffraction patterns suggest high crystalline quality and c-axis orientation. By substitution of trivalent La3+ ions for divalent Ca2+, the resistivity anomaly in the parent compound CaFe2As2 is completely suppressed and a superconducting transition reaches the value of 42.7 K, which is higher than that of about 30 K reported in Saha S. R. et al., arXiv:1105.4798v1. The upper critical field has been determined with the magnetic field along ab-plane and c-axis, yielding an anisotropy of about 3.3.