We have studied the range of Nd-Sm solid solution in the (Nd1-x,Smx)4-2yBa2+2y Cu2-yOz system in the Nd123 matrix. X-ray diffraction studies for the sintered (Nd1-x,Smx)4-2yBa2+2y Cu2-yOz powders in air showed that the samples were a single phase 422 in the range of x = 0-0.3, showing that Sm substituted on Nd site in Nd422. It was also found that Sm is soluble up to x = 0.3 in (Nd1-x,Smx)3.6Ba2.4 Cu1.8Oz. We then fabricated Nd123/Nd422 bulk superconductors by melt processing, in which Nd123 powder is mixed with 20 mol% (Nd0.8,Sm0.2)3.6Ba2.4 Cu1.8Oz and 1 wt.% CeO2. The sample exhibited high Tc of 97 K and sharp superconducting transition when melt-processed under controlled oxygen partial pressure (PO2) of 0.01 atm.
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