Structure, superconducting and magnetotransport properties of Ru1−xSnxSr2Gd1.4Ce0.6Cu2Oy (0≤x≤0.1)

Samples with nominal compositions Ru1−xSnxSr2Gd1.4Ce0.6Cu2Oy (0≤x≤0.1) were synthesized and their structure, superconducting and magnetotransport properties were investigated. It was shown that the Sn-doping enhances the crystal growth in Ru-1222. A maximum in the dependences of the lattice parameters and Tc on the dopant content x was observed. Small doping levels significantly increase the Tc of the Ru-1222 samples, prepared at the same conditions—from 20 K for the undoped sample to 35 K for the x = 0.02 and 0.03 ones. It was found that the Sn-doping enhances the upper critical field Hc2(0), extrapolated to T = 0, and the weak link behavior at the expense of the intragranular superconductivity in Ru-1222. The observed phenomena are discussed.