Effect of heat treatment condition on the phase formation of YBa2Cu3O7-δ superconductor
Polycrystalline samples with the nominal composition YBa2Cu3O7-δ (Y-123) were prepared using the co-precipitation method. The effect of the calcination process (single and multiple calcinations) on the samples was investigated by using the four-point temperature-resistance measurement, x-ray diffrac...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Trans Tech Publications
2017
|
| Online Access: | http://psasir.upm.edu.my/id/eprint/13462/ http://psasir.upm.edu.my/id/eprint/13462/1/Effect%20of%20heat%20treatment%20condition%20on%20the%20phase%20formation%20of%20YBa2Cu3O7-%CE%B4%20superconductor.pdf |
| Summary: | Polycrystalline samples with the nominal composition YBa2Cu3O7-δ (Y-123) were prepared using the co-precipitation method. The effect of the calcination process (single and multiple calcinations) on the samples was investigated by using the four-point temperature-resistance measurement, x-ray diffraction (XRD) and field-emission scanning electron microscope (FESEM). This study is divided into two parts. For the first part, the obtained oxalate powder underwent two calcination processes at 900 °C for 12 h and 900 °C for 24 h, respectively. Then, the powders were pressed into pellets and sintered at 920 °C for 15 h with oxygen flow during the entire heat treatment. In the second part, only one calcination process was undertaken at 900 °C for 24 h before the sintering process in oxygen flow at 920 °C for 15 h. From the XRD patterns, all of the peaks were indexed to the Y-123 phase showing that this superconducting phase was already formed after the first calcination. The volume fraction of Y-123 of the samples with single calcination process was higher compared to multiple calcination processes. From the temperature-resistance measurement, all the samples showed metallic behavior in the normal state and a superconducting transition to zero resistance. The superconducting transition temperature, Tc, for the samples prepared in a single calcination process is higher than that of the multiple calcination processes. |
|---|