Key issues for the characterization of RE-Ba-Cu-O systems (RE: Nd, Sm, Eu, Gd)

In this review, several key issues which are important in understanding materials properties of RE-Ba-Cu-O were raised. The fact that RE-Ba-Cu-O exhibits a RE-Ba solid solution is the most important and should be carefully taken into consideration for the characterization of materials. The preparation procedures of precursor materials are also critical and strongly affect the microstructure and superconducting properties of the final products. Melt processing and oxygen annealing conditions also have a large effect on the superconducting properties. Therefore, for fully understanding the superconducting properties of RE-Ba-Cu-O, we should clarify the relation between processing parameters and the microstructural features.