Effects of nanometer yAl203 addition on superconducting properties of Bi16Pbo.4Sr2Ca2Cii30x (Bi-2223) superconductor / Masnita Mat Jusoh

• Main Author: Mat Jusoh, Masnita
• Format: Thesis
• Language: English
• Published: 2011
• Subjects: Superconducting materials. Superconductors
• Online Access: https://ir.uitm.edu.my/id/eprint/65193/1/65193.pdf; https://ir.uitm.edu.my/id/eprint/65193/

Copper oxide based superconductor Bismuth (Bi, Pb)SrCaCuO or well known as (BSCCO-2223) with nano-yA^C^ addition have been prepared via co-precipitation (COP) method. The precursor powder was prepared using COP method while addition of nanoparticles yA^Os was done through solid state reaction method. Four point probe, X-ray diffraction (XRD), energy dispersive analysis (EDAX) and scanning electron micrograph (SEM) have been used to characterize the materials. By COP method, the precursor was fabricated into bulk samples and the addition of nano-yA^Os is between 0.0 wt% -1.0 wt % from molecular weight of sample. All prepared samples have been sintered in various sintering duration of 12, 24, 36, 48 and 56 hours at 850°C, respectively. The focus of investigation is on critical transition temperature (Tc), critical current density (Jc), Bi-2223 phase percentage and microstructure development. All four characteristics have been studied for each experimental sample. Sample with addition 0.7 wt% of nano-yAl203 and sintered at 48 hours shows maximum Jc value of 9.78 A/cm2 with Tc of 101 K. Jc value depends on sintering duration. Sample sintered for 12 hours at 850°C did not show superconductivity properties very well. The Jc obtained is 3.7 A/cm2 and the Tc is lower than 90 K. The COP method has shown to produce high percentage of Bi-2223 superconducting phase. A small addition of nano-yAl203 is found to improve the Bi-2223 phase where intergrains connectivity is enhanced and weak links are reduced, resulted in enhanced Jc value. Larger grains size is observed with increasing sintering time as manifested in samples sintered at 56 hours. In COP prepared samples, the nanoparticles act as pinning flux centre under certain condition.