The thermal/electronic transport properties of new superconductor MgB2 and MgCNi3
新型超导体MgB2和MgCNi3热、电输运性质研究

The temperature dependence of thermal conductivity and electronic conductivity in superconductor MgB2, MgCNi3 and Bi2Sr2Ca0.9Ce0.1Cu2O8+y are presented. The thermal conductivity of Bi2Sr2Ca0.9Ce 0.1Cu2O8+y shows a peak under Tc observ ed in cuprates, but those of MgB 2 and MgCNi3 decrease monotonously. We calculate the elec tron thermal condu ctivity and the phonon thermal conductivity by Wiedemann-Franz law. The electron s contribute a large fraction to the thermal conductivity in normal state of MgB 2 and MgCNi3 because of the non-localigation of mutual eff ect of electrons. The analysis on electronic thermal conductivity indicates that the scattering by impurities prevails in electronic thermal resistance of both samples.