| Автор | T W Button |
| Автор | N McN Alford |
| Автор | J D Birchall |
| Автор | F Wellhofer |
| Автор | C E Gough |
| Автор | D A O'Connor |
| Дата выпуска | 1989-10-01 |
| dc.description | Superconducting Bi-Pb-Sr-Ca-Cu-O ceramics have been prepared at the Bi<sub>1.2</sub>Pb<sub>0.8</sub>Sr<sub>2</sub>Ca<sub>2</sub>Cu<sub>3</sub>O<sub>x</sub> (2223) and Bi<sub>1.6</sub>Pb<sub>0.4</sub>Sr<sub>2</sub>Ca<sub>3</sub>Cu<sub>4</sub>O<sub>y</sub> (2234) compositions. The properties and microstructures after sintering in air at 850 degrees C for times from 2 to 156 hours are described and compared. For the 2223 composition all heat treatment times result in multiphase samples. Bulk superconductivity giving zero resistance at 106 K and a maximum J<sub>c</sub> of 300 A cm<sup>-2</sup> at 77 K is achieved after 50 h heat treatment. When sintered in excess of 40 h samples of the 2234 composition consist predominately of the high-T<sub>c</sub>, n=3, phase. J<sub>c</sub> is again maximised after 50 h heat treatment but at lower value of 150 A cm<sup>-2</sup> and T<sub>c</sub>(R=0)=103 K. For longer sintering times J<sub>c</sub> of the 2234 composition falls to zero after approximately 100 h at 850 degrees C. Samples of both compositions densify rapidly during the first two hours of sintering. Further heat treatment results in a large de-densification, the reasons for which are described in detail. A decrease in lead content with increasing sintering time is observed. The implications of these observations for the production of high-quality, bulk Bi-Pb-Sr-Ca-Cu-O superconducting ceramics are discussed. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | A comparison of lead-doped Bi-Sr-Ca-Cu-O superconductors at the '2223' and '2234' compositions |
| Тип | paper |
| DOI | 10.1088/0953-2048/2/4/005 |
| Electronic ISSN | 1361-6668 |
| Print ISSN | 0953-2048 |
| Журнал | Superconductor Science and Technology |
| Том | 2 |
| Первая страница | 224 |
| Последняя страница | 229 |
| Аффилиация | T W Button; ICI Adv. Mater., Runcorn, UK |
| Аффилиация | N McN Alford; ICI Adv. Mater., Runcorn, UK |
| Аффилиация | J D Birchall; ICI Adv. Mater., Runcorn, UK |
| Аффилиация | F Wellhofer; ICI Adv. Mater., Runcorn, UK |
| Аффилиация | C E Gough; ICI Adv. Mater., Runcorn, UK |
| Аффилиация | D A O'Connor; ICI Adv. Mater., Runcorn, UK |
| Выпуск | 4 |
