Domain growth in partially melted bulk Nd1+xBa2−xCu3O7−δ

Domain growth of bulk partially melted Nd1+xBa2−xCu3O7−δ in air was found to be severely limited by liquid-phase segregation and losses. The use of a reduced oxygen pressure greatly improved the stoichiometry control, leading to the formation of well-developed domains and enhanced superconducting properties. Direct nucleation of Nd1+xBa2−xCu3O7−δ from the liquid phase by dissolution of Nd2BaCuO5 and a spiral growth mechanism in three perpendicular directions of the platelets stacked in the domains, are suggested.