| Автор | N J C Ingle |
| Автор | D A Cardwell |
| Автор | A R Jones |
| Автор | F Wellhofer |
| Автор | T W Button |
| Дата выпуска | 1995-05-01 |
| dc.description | Magnetic properties of melt-processed YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7- delta </sub> thick films have been measured and correlated with features in the microstructure at 4.2 and 77 K for film thicknesses between 50 and 140 mu m. A pronounced peak has been observed in both the measured volume magnetization and calculated length scale over which current flows at a film thickness of approximately 53 mu m and 4.2 K in fields of up to 10 T. An intra 'hub-spoke' (H-S) type grain current dominates the volume magnetization at this film thickness. Measurements at 77 K, on the other hand, exhibit a peak at 80 mu m, the magnitude of which varies significantly with applied field. This correlates well with observed increased connectivity between individual H-S grains and may be accounted for by the flow of inter H-S grain current. The H-S grains transform to a more granular microstructure for films greater than approximately 100 mu m thick which is characterized by the presence of smaller diameter current-carrying loops. This is observed as a decrease in the volume magnetization at 4.2 K and a levelling off of this parameter at 77 K with increasing film thickness. Further evidence for the presence of intra H-S and inter H-S grain critical current densities at 4.2 K in films up to a thickness of 80 mu m has been observed from length-scale analysis as a function of the difference between maximum and applied magnetic field. A qualitative model for the volume magnetization of the films at 4.2 K in terms of individual contributions from intra H-S grain, inter H-S grain and granular J<sub>c</sub> components is proposed. |
| Формат | application.pdf |
| Издатель | Institute of Physics Publishing |
| Название | The effect of thickness on the magnetic properties of melt-processed YBCO thick films |
| Тип | paper |
| DOI | 10.1088/0953-2048/8/5/003 |
| Electronic ISSN | 1361-6668 |
| Print ISSN | 0953-2048 |
| Журнал | Superconductor Science and Technology |
| Том | 8 |
| Первая страница | 282 |
| Последняя страница | 290 |
| Аффилиация | N J C Ingle; Interdisciplinary Res. Centre in Superconductivity, Cambridge Univ., UK |
| Аффилиация | D A Cardwell; Interdisciplinary Res. Centre in Superconductivity, Cambridge Univ., UK |
| Аффилиация | A R Jones; Interdisciplinary Res. Centre in Superconductivity, Cambridge Univ., UK |
| Аффилиация | F Wellhofer; Interdisciplinary Res. Centre in Superconductivity, Cambridge Univ., UK |
| Аффилиация | T W Button; Interdisciplinary Res. Centre in Superconductivity, Cambridge Univ., UK |
| Выпуск | 5 |
