The effects of barium substitution for Bi or Sr sites on the growth of superconducting phases have been studied. The sol spray process has been used to synthesis the Bi-Sr-Ca-Cu-O (BSCCO) and Ba-BSCCO homogeneous ceramic powders. Thermogravimetric (TG), differential thermal analysis (DTA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques were employed to characterize the synthesized materials. The electrical resistance was measured by classical d.c. fourprobe technique. It has been observed that sol spray process has affected the physico-chemical properties of the materials and also avoid the use of chelating agent as in the case of sol gel process. In addition to the Bi2Sr2CaCu2O8 (2212) phase Ba doped specimens also contained Bi2Sr2Ca2Cu3O10 (2223), BaBiO3, BaCuO2 and CuO phases. The results revealed that the specific effect of barium-doping on either sites (Bi or Sr) seems to avoid the formation of higher volume fraction of the low T c phase and promoting the formation of BiBaO3, BaCuO2 and CuO along with formation of a high T c 2223 phase. The substitution of Ba on either sites (Bi or Sr) lower the sintering temperature for the formation of high T c (small volume fraction) however, the Ba doped specimens also contained non-superconducting phases.
研究了
钡取代 Bi 或 Sr 位点对超导相生长的影响。溶胶喷涂工艺已用于合成 Bi-Sr-Ca-Cu-O (
BSCCO) 和 Ba-
BSCCO 均质陶瓷粉末。采用热重(TG)、差热分析(DTA)、X射线衍射(XRD)、扫描电子显微镜(
SEM)技术对合成材料进行表征。电阻通过经典直流测量。四探针技术。据观察,溶胶喷涂工艺影响了材料的物理
化学性质,并且还避免了与溶胶凝胶工艺一样使用
螯合剂。除了 Bi2Sr2CaCu2O8 (2212) 相之外,Ba 掺杂样品还含有 Bi2Sr2Ca2Cu3O10 (2223)、BaBiO3、BaCuO2 和 CuO 相。结果表明,在任一位点(Bi 或 Sr)掺杂
钡的特定效果似乎避免了低 T c 相的较高体积分数的形成,并促进 BiBaO3、BaCuO2 和 CuO 的形成以及高 Tc 相的形成。 Tc 2223 相。 Ba 在任一位点(Bi 或 Sr)的替代降低了形成高 T c (小体积分数)的烧结温度,然而,Ba 掺杂样品还包含非超导相。