Optical emission studies and preparation of high Tc TlCaBaCuO thin films

✍ Scribed by W.Y. Lee; J.R. Salem; V.Y. Lee; T.C. Huang; R. Savoy

• Publisher: Elsevier Science
• Year: 1989
• Tongue: English
• Weight: 154 KB
• Volume: 162-164
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(89)91186-6

✦ Synopsis

Thin films of TI-Ca-Ba-Cu oxide were sputter-deposited from dual oxide targets using a symmetrical RF diode sputtering system. Spatially resolved optical emission spectra obtained using a scanning optical fiber for CuO, BaO-doped CuO, and T1-Ca-Ba-Cu-O targets suggest no significant bombardments of the growing film by energetic particles in the plasma, resulting in a film composition close to that of the sputtering targets used. The superconducting properties of these films were found to depend strongly on the post-annealing conditions as a result of a substantial loss of thallium during annealing. Itighly textured c-axis oriented films comprised mostly of TI2Ca2Ba~CuaO , with a zero resistance T¢ of 122 K have been synthesized on MgO substrates by annealing in a sealed quartz tu~be of~lms wrapped in gold foil with "rl2Ca2Ba2Cu~O x powders.