Cooling rate effect on microstructure and superconducting properties of pure and SiC doped MgB2 superconductors

Pure and 10 wt.% SiC added bulk MgB2 samples were sintered at 750 Degrees C for 1 h. Cooling of samples to room temperature was performed in different times (rates) such as 0 h (quench), 0.3 h (2433 Degrees C/h), 14 h (52 Degrees C/h), and 25 h (30 Degrees C/h). Correlations between changes in microstructure and superconducting properties have been observed and explained for both pure and SiC added MgB2 samples. On the basis of our experimental results, we have concluded that the cooling rate can be an important parameter influencing superconducting properties of MgB2 samples.