Superconductivity in the RTlSrCuO system with R = rare earths

Abstract

Superconductivity above 40 K has been observed by low frequency ac susceptibility and resistance measurements in the RTlSrCuO system with R = La, Pr, Nd, and Y. Powder x-ray diffraction analyses for a nominal La 2Tl 2Sr 2Cu 3O 10 sample and a nominal Pr 2Tl 2Sr 2Cu 3O 10 sample showed that they were nearly single phase, and can be indexed to a tetragonal unit cell with a=3.775±0.005 A ̊ and c+35.35±0.05 Å, and with a=3.762±0.005 A ̊ and c=35.34±0.05 A ̊ , respectively.