The XRD analyses for the Bi-Pb-Sr-Ca-Ba-Cu-O system show that the addition of Ba ions is favourable to the formation of the higher-Tc phase (Tc>100 K), and TEM observations show that the partial substitution of Ba ions for Ca ions induces a change in the crystal microstructure of the higher-Tc phase (Tc>100 K); a new modulation mode with a wavelength of 43 AA appears in the electron diffraction pattern of the higher-Tc phase. The EDS results confirm that Ba ions really intercalate into the crystal of the 2:2:2:3 phase. The DC magnetization measurements show that the sample displays a much larger hysteresis than that of a general Pb-doped sample. In addition, a study on the influence of low DC magnetic fields on the real component chi ' and imaginary component chi " of the susceptibility for the Ba-doped sample shows that Tp is related to the applied field HDC and their relation can be fitted by (1-Tp/Tc) varies as H0.23 when H DC<140 G, and (1-Tp/Tc) varies as H 0.65 when HDC>140 G. These data can be excellently interpreted in terms of Bean's critical-state model.
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics