95 K NdBCO Single Crystal Grown in Air by Controlling Liquid Composition

Abstract

Using the crystal pulling method, we achieved high superconducting transition temperatures ( T c ) of Nd 1+ x Ba 2- x Cu 3 O 6+δ (NdBCO) single crystals in air. By controlling the liquid composition of the ratio of Ba to Cu (Ba/Cu) at approximately 0.80, the NdBCO crystal displays high T c of about 95 K with a sharp transition width Δ T of less than 0.5 K. The high Ba/Cu in the liquid leads to the low amount of substitution of Nd for Ba, and consequently results in high superconducting properties. This finding suggests that the Ba/Cu in the liquid is a very important processing parameter for the NdBCO system.