Effect of nano-SnO2 particles on structral properties of (Bi,Pb)-2223 superconducting ceramics

In this work, superconducting samples of Bi1.7-xPb0.3SnxSr2Ca2Cu3Oy added by nano-tin dioxide were prepared by conventional solid-state reaction method. The phase formation and volume fraction were characterized using X-ray powder diffraction (XRD) measurements, the microstructure examination, surface morphology analyses of the samples were carried out using scanning electron microscope (SEM), respectively. The critical temperature (Tc) of tin dioxide doped samples were determined with ac susceptibiliy system. Onset temperatures of samples are 108.559 K, 109.985 K, 101.281 K, 101.670 K and 92.676 K respectively. AC susceptibility measurements were shown that the critical temperature increased up to tin dioxide nano-particles doped sample x equals 0.05 and decreased with increasing tin dioxide nano-particles addition. It was observed from SEM micrographs that plate-like structures have been replaced by more disordered structures to doped samples from undoped sample. It was shown from XRD patterns that superconducting samples have multi-phases. The density values of all the samples were calculated with the Archimedes method. In the literature, the theoretical density of BSCCO system is 6.3 grams per cubic centimeter. The densitiy values of samples in this work because of the porous structure were determined to be 5.2006, 5.3438, 5.3056, 5.2802 and 5.2324 grams per cubic centimeter.