The influence of sintering temperature on the critical transition temperature T c and critical current density J c for the MgB 2 superconductor was investigated systematically with the observation of Raman scattering measurement and flux pinning force F p analysis. The enhanced E 2g mode in Raman spectra with increasing in situ sintering temperature shows gradual strengthening of the electron-phonon coupling in MgB 2 , which means that the crystals become more harmonic after higher temperature sintering. However, the crystal harmonicity is degraded for samples sintered at even higher temperature due to Mg deficiency. A possible explanation for the J c ͑H͒ performance, which is in accordance with the Raman spectroscopy observation and F p analysis, is the cooperation between the electron-phonon coupling in the E 2g mode and the flux pinning centers, mainly originating from the lattice distortion due to the different sintering temperatures.

The superconductivity of nano- SiC doped MgB 2 sintered in pulsed magnetic field (PMF) was investigated with Raman scattering measurements and Raman spectral fit analysis. The critical transition temperature, Tc, for the sample sintered in 5T PMF is improved compared with that of the sample sintered without PMF. The high Tc is attributed to the strengthening of the electron-phonon coupling (EPC) in MgB 2, as reflected by the broadened E2g mode in the Raman spectra. The EPC constants are estimated as 0.876 and 0.874, with the electron-E2g coupling contribution 2.30 and 2.25, respectively. Magnetic field processing technology has been proved to be a powerful tool to improve the superconducting properties of SiC -doped MgB 2 superconductor.

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