Comparison of One-Zone and Two-Zone Thalliation Processes in the Tl2Ba2CaCu2Ox Superconducting Thin Films

H. C. Lai；C. M. Chang；R. S. Liu

Chinese Journal of Physics

34卷2S期（1996 / 04 / 01）

271 - 274

英文

Superconducting Tl2Ba2CaCu2Ox, (2212) thin films have been prepared on (110) MgO substrates using ex-situ one-zone and two-zone thalliation processes. The Tl2O vapour pressure was adjusted by either thalliation temperature (one-zone method; or the position of the thallium source (two-zone method). The thalliation conditions were set between 830 and 880℃ with various periods of time. Thalliated Tl2Ba2CaCu2Ox films with Tc0 values of around 102 K and Jc (77 K) up to 5 x 10^5 A/cm^2 have been obtained. On consideration of controlling thallium vapour pressure, we find that the two-zone thalliation process is relatively simple and straight forward. which can be very helpful for controlling grain structure.