Identification of single-domain structures in the system YBa 2 Cu 3 O 7-δ -Ag by magnetization measurements

Abstract The magnetization methods were used in study of effect of Ag doping on the structural and superconducting parameters in two series of melted and highly textured samples of the system (YBa 2 Cu 3 O 7−δ ) 1-x (Ag 2 O) x . The x concentration level of the first series ranged from 0 to 10 wt % and the second one from 0 to 3.6 wt % Ag 2 O. By means of the SQUID magnetization measurements the optimum Ag 2 O doping level ranged from 1.6 to 2.8 wt %. These methods led to optimization of conditions in preparation of single-domain samples. From the secondary precipitated CuO phase and from the appearance of Ag component the solubility limit of Ag in solid solution YBa 2 Cu 3−y Ag y O 7−y/2−δ was found

Study of light nonstoichiometry in Eu-Ba-Cu-O systems

We studied effects of light Eu-Ba nonstoichiometry in Eu-Ba-Cu-O superconducting compounds on their transition, structural, and magnetic properties. Two series of Eu1+xBa2-x Cu3O7+delta and Eu1-x Ba2+xCu3O7+delta samples with x = 0, 0.01, 0.02, 0.04, 0.05, 0.07 and 0.1 were synthesized by the solid-state reaction method from Eu2O3, BaCO3 and CuO precursors and sintered at 1050 degrees C for 72 h in flowing oxygen. Structural, transition, and magnetic properties were investigated by means of X-ray diffraction, resistance, mutual inductance, magnetization and optical measurement methods. The Eu-Ba nonstoichiometry in the two series results in different effects on transport, magnetization, grain, intergrain and microstructure properties of the samples in relation to the substitution level of x. All the samples show the values of critical temperature T-c, volume density rho, and maximum volume magnetization M-max higher than 91 K, 6.4 g cm(-3) and 10(4) Am-1, respectively

Effects of Eu-Ba nonstoichiometry in Eu1+xBa2-xCu3O7 +/-delta system on structural and magnetization properties

We have studied effects of Eu-Ba nonstoichiometry in Eu1+xBa2-xCU3O7 +/-delta system on structural and magnetic properties. Polycrystalline samples Eu1+xBa2-xCu3O7 +/-delta (0 = 0.05, there are significant changes in magnetization values and magnetization hysteresis