Preparation of RBa₂Cu₃O_y (R=Y, La, Nd, Sm, Eu, Gd, Dy, Ho, Er and Yb) Superconductors Using a Microwave Oven

Abstract

The rapid preparation of a series of RBa₂Cu₃O_y (R=Y, La, Nd, Sm, Eu, Gd, Dy, Ho, Er and Yb) superconductors on the microwave processing was studied. All of the RBa₂Cu₃O_y superconductors were prepared as orthorhombic compounds and it was found that these compounds, except for the case of La, have revealed the superconductivities with the superconducting transitions, (T_cmag), ranging from 83 to 93 K. The T_cmag for compounds RBa₂Cu₃O_y (R=Dy, Y and Ho) remained essentially constant at 93 K, independent of R. However, the T_cmag decreased with increasing R radius andwith decreasing R radius. Further we have attempted to prepare Nd_xYb_1-xBa₂Cu₃O_y of two rare earth elements with different ionic radii and also have investigated the superconducting properties of the synthesized compounds in various compositions of x (0≤x≤1). The cell parameters showed linear dependence on the composition (x). In the range of x=0.2-0.4, a homogeneous phase superconductor with T_cmag=93 K was formed, while for the range of x≥0.5, the T_cmag clearly decreased with increasing x and reached a value of 83 K in the sample with composition of NdBa₂Cu₃O_y.