STUDY ON THE THERMOPOWER AND RESISTIVITY OF A NEW SUPERCONDUCTOR MgB2

The temperature-dependent thermopower and resistivity of MgB2 were measured.In the range of 100—300K, the thermopower presents positive nearly linear temperature dependence,indicating that the charge carrier is hole and it is consistent with the energy band pattern.In contrast,the resistivity follows T2 relationship in the same temperature range.Below 100K,thermopower and resistivity change their temperature dependence.The thermopower presents a hump between the superconducting transition temperature Tc (zero resistance,36.6K) and 100K.It has the characteristic of the phonon drag,indicating the strong electron-phonon interaction.Some important parameters are estimated according to experimental results,such as Fermi energy EF and energy band width.