SYNTHESIS OF YBA2CU4O8 CERAMICS AT ONE ATMOSPHERE PRESSURE IN OXYGEN

Bulk Y124 high-Tc superconductor has been synthesized by solid state r eaction of a mixture of Y2O3, Ba(NO3)2 and micron size CuO at one atmo sphere oxygen pressure with addition of NaNO3. There is no intermediat e grinding in the process. Samples have been studied by electrical, ma gnetic, x-ray, SEM, and EDX measurements. The x-ray diffraction patter n reveals that the final product is an essentially phase-pure material , except for weak line near 30-degrees (2theta), all the observed diff raction peaks could be identified in terms of the known crystal struct ure for Y124. The samples with a transition onset of 80K reached zero resistance at 72K.