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

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 the superconducting transition temperature 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 the ab-plane and c-axis, yielding an anisotropy of about 3.3. Copyright (C) EPLA, 2011