ساخت نانو بلورک‌های δ-7O3Cu2YBa به روش مکانوشیمیایی و بررسی دمای گذار ترکیبات -7O3Cu2YBa(x-1) + 2 xMnO (02/0 ،015/0 ،01/0 ،005/0 ،0 = x)

In this research, YBa2Cu3O7-d (0 < d < 1) nanocrystalite superconductor was prepared by mechanochemical alloying method. We synthesized YBa2Cu3O7-d via mixing the BaCO3, Y2O3, 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-d 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.ر