The syntesis of YBa2Cu3O7- nanocrystalites via mechanochemical alloying & study transition temperature of xMnO2 + (1-x) YBa2Cu3O7- compounds

In this research, YBa2Cu3O7- (0 <  < 1) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7- via mixing the BaCO3, 2O3, CuO powders and milling in SPEX 8000 for 5h with weight ratio of ball to powder 10:1 and steel balls of 11mm diameter, followed by heating for 4h at 850 @C. 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- 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.