Effect of Eu(Pr) substitution at Ba sites on microstructure and superconductivity in EuBa2Cu3O7-δ ceramics

Ceramics of Eu1+xBa2-xCu3O7-delta with x = 0.0, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5 and EuBa2-xPrxCu3O7-delta with x = 0.0, 0.05, 0.1, 0.2, 0.3, 0.4 have been synthesized and investigated by X-ray diffraction, resistivity, and Raman spectroscopy. The results show that the transition of crystal structure from orthorhombic to tetragonal occurs and the critical temperature decreases with the increase in doping concentration x. The Raman spectra show that the frequency of the Cu(1)-O(4) stretching mode and the Cu(2)-O(2, 3) out-of-phase mode shifts to higher wave number with increasing doping concentration x.