Tl-based superconducting films prepared by aerosol spray deposition and thallinated in an open system
| Autor: | Vladimír Štrbík, Zuzana Matkovičová, M. Valerianova, Gustav Plesch, Agáta Dujavová |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: |
Superconductivity
Resistive touchscreen Aerosol spray Materials science tl-based superconducting film Annealing (metallurgy) Physics QC1-999 74.72.jt Analytical chemistry General Physics and Astronomy chemistry.chemical_element 74.78.bz tl-2212 tl-2223 Oxygen Spray pyrolysis law.invention chemistry.chemical_compound Nitrate chemistry Impurity law 74.78.-w spray pyrolysis |
| Zdroj: | Open Physics, Vol 5, Iss 3, Pp 398-404 (2007) |
| ISSN: | 2391-5471 |
| Popis: | Superconducting Tl-based films were prepared on a LaAlO3 single crystal substrate. Spray pyrolysis of Ba, Ca and Cu nitrate solutions was used for deposition of the precursor films. They were subsequently ex-situ thallinated in flowing oxygen (open system). While the superconducting Tl-2212 phase formed at an annealing temperature of 880°C, thallination at 900°C led to the formation of a Tl-2223 /Tl-2212 mixture. The amount of Tl-2223 increased with prolonged thallination, whereas the Tl-2212 phase progressively disappeared. Films prepared in such a manner were c-oriented and contained only low amounts of non-superconducting impurities. The resulting samples were characterized by XRD and SEM and their T C values were determined by resistive four-point measurements. They showed critical temperatures in the range of T ON = 125–135 K, T C0 = 91–93 K. Differences between the composition and properties of the obtained films and those thallinated in closed systems under 50 kPa of oxygen are discussed in this paper. Results show that the Tl-2212 → Tl-2223 transformation proceeds at a slower rate under flowing oxygen than in a closed system. |
| Databáze: | OpenAIRE |
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