Solid state phase transformation of Nd1+xBa2-xCu3O6+delta during annealingprocessing

In order to investigate solid state phase transformation in solid, Nd1-xBa2 -xCu3O6+delta powders with different compositions were annealed under diffe rent annealing conditions. The temperature-substitution ratio-oxygen conten t phase diagram of Nd1+xBa2-xCu3O6+delta solid solution was constructed. Th e condition to occur Nd123ss phase separation was clarified by investigatin g the compositional fluctuation, XRD pattern, the time dependences of T-c p roperties and oxygen content. Solid state phase transformation of Nd123ss a dvances with two steps. Tetragonal orthorhombic phase transition due to oxy gen introduction occurs at first, and then the orthorhombic phase with smal l x decomposes to the two phases by spinodal decomposition.