Crystal growth and structural study of superconducting Bi-2212 significantly under-doped
Event details
| Date | 03.09.2015 |
| Hour | 09:00 › 10:00 |
| Speaker | Johanie Uccelli, Faculty of Science, Dept. of Quantum Matter Physics, Univ. Geneva |
| Location |
PPB 019
|
| Category | Conferences - Seminars |
The principal goal of my Master Thesis work was to synthesise superconducting crystals in under-doped region of the cuprates phase diagram. Single crystals of under-doped Bi-2212 were grown by the floating zone method using an image furnace. The growth was performed at a travelling velocity of 0.2mm/h. in a two-mirror furnace with a temperature gradient at the liquid-solid interface of about 50°C/mm. The grown crystals were cleaved of typical 1-3 mm size and were characterized using a x-rays diffractometer, a superconducting quantum interference device (SQUID) and a scanning electron microscope (SEM). To perform the under-doping of the crystals we followed two routes: either we used trivalent ions of yttrium, praseodymium and neodymium to partially replace calcium, or we annealed the crystals under low pressure of oxygen. After the SQUID measurements we observed large susceptibility transitions for the under-doped compounds and the SEM data confirm an inhomogeneity of the chemical compounds in the samples.
Practical information
- Informed public
- Free
Organizer
- Prof. P. Ricci
Contact
- Prof. P. Ricci