Preparation of oriented high-T c Tl-Ca-Ba-Cu-O thin films from co-condensed amorphous Ca-Ba-Cu alloys by post-deposition oxidation and Tl diffusion

Abstract
Single‐phase Tl2Ca1Ba2Cu2O8 thin films with zero‐resistance transition temperature up to 100 K have been prepared on single‐crystal MgO substrates from codeposited Ca‐Ba‐Cu amorphous metallic alloy precursors. After thermal oxidation of the metallic alloy film, Tl from Tl2O3 was vapor deposited and diffused into the resulting mixed metal oxide during a rapid high‐temperature anneal. The films prepared in this process are highly oriented with the c axis normal to the substrate.