| Автор | G K Padam |
| Автор | B Gogia |
| Автор | K B Ravat |
| Автор | S N Ekbote |
| Автор | B K Das |
| Дата выпуска | 1995-05-01 |
| dc.description | A high-temperature (HT) superconducting transition around 120 K and enhanced T<sub>c</sub> (R=0) were obtained in bulk polycrystalline Bi<sub>1.6</sub>Pb<sub>0.4</sub>Sr<sub>2</sub>Ca<sub>1</sub>Cu<sub>2</sub>O<sub>8+x</sub> samples. In order to understand the physical origin of the HT transition, different studies such as (i) XRD, TEM/SAD, SEM and EDAX and (ii) effects of post-sintering treatments in O<sub>2</sub> and Na atmospheres and Ca-excess incorporation have been carried out. From all the structural, microstructural and compositional studies, it appears that the major superconducting bulk consists of Bi-2212 phase without any noticeable amount/intergrowth of the most expected second phase (e.g. Bi-2223) in the sample. Moreover, observed behaviours, which are not expected from the Bi-2223 phase, such as displacement of the HT transition and change in T<sub>c</sub> (R=0) value towards (i) high-temperature side on N<sub>2</sub> and (ii) lower temperature side on O<sub>2</sub> annealing and on Ca-excess incorporation suggest that both the HT transition and enhanced T<sub>c</sub> (R=0) are not because of any Bi-2223 phase and on the contrary indicate that they are due to the low-T<sub>c</sub> Bi-2212 phase. In addition, the increase in the commensurate modulation periodicity observed from SAD studies suggests that the increase in the order due to an ordered arrangement of oxygen vacancies has resulted in T<sub>c</sub> enhancement of the Bi-2212 phase. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | The high temperature transition and enhanced T<sub>c</sub> (R=0) in Bi<sub>1.6</sub>Pb<sub>0.4</sub>Sr<sub>2</sub>Ca<sub>1</sub>Cu<sub>2</sub>O<sub>8+x</sub> |
| Тип | paper |
| DOI | 10.1088/0953-2048/8/5/014 |
| Electronic ISSN | 1361-6668 |
| Print ISSN | 0953-2048 |
| Журнал | Superconductor Science and Technology |
| Том | 8 |
| Первая страница | 354 |
| Последняя страница | 360 |
| Аффилиация | G K Padam; Nat. Phys. Lab., New Delhi, India |
| Аффилиация | B Gogia; Nat. Phys. Lab., New Delhi, India |
| Аффилиация | K B Ravat; Nat. Phys. Lab., New Delhi, India |
| Аффилиация | S N Ekbote; Nat. Phys. Lab., New Delhi, India |
| Аффилиация | B K Das; Nat. Phys. Lab., New Delhi, India |
| Выпуск | 5 |
