Superconducting behaviours of melt textured Nd(1+x)Ba2-xCu(3)O(y) undergoing heat treatments in flowing argon and oxygen

Many studies showed that the preparation of melt textured Nd1+xBa2-xCu3Oy must be carried out in flowing argon in order to obtain the high T-c phase [1,4]. We report that melt textured Nd1-xBa2-xCu3Oy can be obtained through a conventional melt textured process and a following Ar treatment. The melt textured sample is superconducting at 63 K without any following heat treatments. Its critical temperature rises up to 78 K after oxygenation. The sample undergoes a orthorhombic-to-tetragonal phase transition through a flowing Ar treatment. This structure change seems to be useful to increase the critical temperature of the sample. A high critical transition temperature up to 93 K and an onset temperature of 96 K can be obtained through the optimal treating process. Moreover, the oxygenation temperature of melt textured Nd1+xBa2-xCu3Oy is lower than that of melt textured YBCO.