Synthesis and Magnetic Properties of Bi1.7Pb0.3Sr2Ca2Cu3O10+δ Added with Nano Y
Tóm tắt
Bi17Pb0.3Sr2Ca2Cu3O10+δ superconductor samples were synthesized by the conventional solid-state reaction method. To study the effects of the addition of yttrium nanoparticles to the superconducting system, nano Y2O3 was introduced by small weight percentages (0.2, 0.4, 0.6, 0.8, and 1.0 wt%) in the first step of the synthesis process. Phase identification and microstructural characterization of the samples were investigated using X-ray diffraction and scanning electronic microscopy (SEM). Energydispersive X-ray spectroscopy (EDX) analysis was utilized to confirm the presence of the desired elements in the chemical composition of the samples. Moreover, DC electrical resistivity as a function of the temperature, critical current density (J
c), AC magnetic susceptibility, and DC magnetization measurements were carried to evaluate the relative performance of samples. XRD analysis showed that both (Bi,Pb)-2223 and Bi-2212 phases coexist in the samples having an orthorhombic crystal structure. Both the onset critical temperatures (T
c) (onset) and zero electrical resistivity critical temperatures (T
c) (R = 0) of the samples were determined from the DC electrical resistivity measurements. An improvement of the superconducting transition temperature of 3.0 % was obtained with increasing Y2O3 nanoparticles to x = 1.0 wt%, while the critical current density is improved by 200 %. AC magnetic susceptibility measurement showed that the diamagnetic fraction and intergranular coupling of the x = 1.0 wt% sample are greater than those of the others. The variation of magnetization with temperature (M–T curve) of the samples was measured by cooling the sample in zero fields (ZFC) and an applied field of 10 Oe (FC). The results of AC magnetic susceptibility and DC magnetization measurements were in good agreement with DC electrical resistivity measurement.