Dielectric properties of polycrystalline MgB2

The low-frequency (103–105 Hz) dielectric properties of polycrystalline MgB2 were investigated as a function of temperature (25–285 K). The real and imaginary parts of the dielectric constants were higher than 107, and they increased with the decreased temperature. No obvious frequency dependence of the real parts was found, which was consistent with the behavior of a good metal within the Drude model at low frequency. The results indicated the high dielectric constants were from the electrical conductivity of the superconductor.