Resumo

PEREZ-ARRIETA, L et al. Two step synthesis of TlBa₂Ca₂Cu₃O_x films on Ag substrates by spray pyrolysis of metal-acetylacetonates. Rev. mex. fis. [online]. 2008, vol.54, n.6, pp.446-450. ISSN 0035-001X.

A two-step synthesis process was performed to obtain TlBa₂Ca₂Cu₃O_x (Tl-1223) superconductor films. The synthesized films were obtained under different thallium diffusion conditions in a two-zone furnace precursor films were deposited at 550° C on silver substrates using the spray pyrolysis technique from acetylacetonates (2, 4-pentanedionates) as reagents. Second, a thallium diffusion process is carried out to incorporate Tl in the films. For this task Tl₂O₃ pellets, as a Tl source, were used at 750°C. Different oxygen flow rates at atmospheric pressure were used in order to get the thallous oxide p (Tl₂O) partial pressure in the range of 6.9 x 10^-4 to 6.1 x 10^-2 atm. The Tl-1223 phase was obtained in all cases, though for a low p (Tl₂O), the films presented the BaCuO₂ phase mixed with the Tl-1223 one. Critical temperature (T_C) values for these films were in the range of 90 to 102 K.

Palavras-chave : Superconductors; thin films; spray pyrolysis.

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