A NA-INTERVENED SUPERCONDUCTORS AND THEIR PREPARING METHOD

摘要

PURPOSE: A sodium inserted superconductor is provided, which is thermally stable and has high critical current density and high critical temperature. And a method for preparing the same is also provided. CONSTITUTION: The sodium inserted yttriferous superconductor is represented by the following formula (1): (Na1-xYx)(Ba1-yLny)2Cu3O6+δ. In the formula (1), Ln is a trivalent lanthanide except Ce and Pr, x is greater than 0.1 and smaller than 0.9, and y is greater than 0.1 and smaller than 0.3. The method comprises steps of: (i) mixing Y2O3, NaCuO2, BaCuO2, Ln2O3 and CuO; and (ii) oxygen heat-treating the mixture of the step (i) at a temperature of 850-950 deg.C for 30-40 hours.