Temperature dependence of composition ratio of Bi2Sr2CaCu2O8+δ film by PLD method

✍ Scribed by E. Kume; H. Fujino; X. Zhao; S. Sakai

• Publisher: Elsevier Science
• Year: 2004
• Tongue: English
• Weight: 371 KB
• Volume: 412-414
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2004.02.223

✦ Synopsis

We have prepared Bi 2 Sr 2 CaCu 2 O 8þd (Bi-2212) thin films by a pulse laser deposition (PLD) method followed by postannealing. The thin films were grown on MgO substrates at 400-630 °C and 100 mTorr oxygen. They were about 200 nm thick. The crystalline structure of thin films deposited at lower temperature (470 °C) was amorphous. The films deposited at higher temperature (550 °C) began to crystallize (c-axis oriented) but it turned out that Bi decreased with an increase temperature. After deposition, post-annealing were performed at 860-880 °C in a tubular furnace with mixed gas (Ar:O 2 ¼ 93:7, 1 atm, 0.2 l/min flow) for 3 h. Bi did not decrease with the increase of post-annealing temperature up to 870 °C. The critical temperature of film was 78 K, and the root-mean-square (RMS) roughness in 10 lm square was less than 10 nm.