Investigation of characteristics for different film thickness of Bi-2212/MgO fabricated by metal–organic decomposition
✍ Scribed by K. Hamanaka; T. Tachiki; T. Uchida
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 588 KB
- Volume
- 470
- Category
- Article
- ISSN
- 0921-4534
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✦ Synopsis
To apply Bi 2 Sr 2 CaCu 2 O 8+x (Bi-2212) thin films to superconducting devices flexibly, it is important to evaluate the characteristics of films with a different film thickness. Bi-2212 thin films with thicknesses of 40-240 nm were fabricated on MgO substrates by metal-organic decomposition (MOD). Firing conditions were optimized individually for each film thickness. For the films with a thickness of about 40 nm, no significant diffraction peaks were observed in / scans. However, for the films with thicknesses of about 120 nm and 240 nm, dominant rotation angles were g = 45°([1 0 0] of Bi-2212//[1 1 0] of MgO) and g $ ±12°([1 0 0] of Bi-2212//[5 1 0] and [5 1 0] of MgO), respectively. The grain size of Bi-2212 became larger with increasing the film thickness. For the films of 120 and 240 nm, large flat grains with a size larger than 10 lm were obtained. Moreover, the critical current density (J c ) increased with increasing the film thickness. The maximum J c obtained for the films of 240 nm was 1.1 Â 10 6 A/cm 2 at 4.2 K.