The synthesis of YBa2CU3O7-δ nanocrystalites via mechanochemical alloying and study transition temperature of xMnO2 + (1-x) YBa2Cu3O7-δ compounds

In this research, YBa2Cu3O7-δ (0 <δ< l) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7-δ via mixing the BaCO3, Y2O3, Cu O powders and milling in SPEX 8000 for 5h with weight ratio of ball to powder 10:1 and steel balls of 11 mm diameter, followed by heating for 4h at 850degreeC. The superconductor phase formation process was completed with sintering treatment under oxygen partial pressures. The superconducting transition temperature of the samples was investigated using the four-probe method. Then transition temperature of xMnO2 + (1-x) YBa2Cu3O7-δ compounds was studied. The superconducting transition temperature of the final samples with x =0, 0.005, 0.01 is found to be 83 K, and for the samples with x > 0.015, the superconductivity was vanished.