Effect of Pb on the properties of Sr₂YRu_1-xCu _xO₆ crystals grown from PbO-PbF₂ solutions at high temperatures

Single crystals of Sr₂YRu_1-xCu_xO ₆ with x=0 and x=0.1 were grown using PbO-PbF₂ based solutions at different temperatures in the range 1150-1350°C. The influence of Pb from the solutions and the Cu from the solid solutions of Sr ₂YRu_1-xCu_xO₆ on the resulting crystals was studied using microstructure and magnetic property measurements. The peaks in the powder X-ray diffraction patterns and Raman spectra do not change in the case of x=0 crystals but shift in the presence of Cu. A diamagnetic transition indicative of superconductivity was observed in the presence of Cu and an antiferromagnetic behavior with x=0. Based on these results it is concluded that Pb may not be incorporated in the crystals and even if it does the influence is not observed.