YBa2Cu3O7-δ (YBCO) films were grown on LaAlO3 substrates by a metal organic deposition using trifluoroacetates (TFA-MOD). In this study, effects of calcination condition such as temperature on microstructures and Jc properties for the YBCO films were studied. The TFA starting solution was coated on a substrate by a spin-coating method. Then, a two-step heat treatment was applied to the coated films. In the calcination step, the coated film was calcined to form a homogeneous amorphous precursor by increasing the temperature which was varied from 300 °C to 500 °C at a constant heating rate of 2 °C/min. The prepared precursor films were crystallized at a constant condition. As a result, Jc value depended on the calcination temperature, YBCO film calcined at 400 °C showed the highest Jc of 2.5 MA/cm2. Jc's for the YBCO films calcined at 300 °C and 350 °C were 1.9 MA/cm2 and 2.0 MA/cm2, respectively. On the other hand, YBCO film calcined at 500 °C showed the lowest Jc of 1.4 MA/cm2. Cross-sectional TEM images showed that the YBCO film calcined at 400 °C had less pores and small size of pores in the crystallized film randomly throughout the film. Large pores were observed in the YBCO film calcined at 500 °C. Also, these large pores were existed near substrate in the YBCO film. It is considered that the differences of these pore formation mechanisms are the main cause of the difference of Jc characteristic.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering