新型超导体MgB2和MgCNi3热、电输运性质研究

报道了两种新型超导体MgB₂,MgCNi₃和氧化物高温超导体Bi_{2< /sub>Sr2Ca0.9Ce0.1Cu2O8+y 的热导率-温度关系和电阻率-温度关系.实验发现氧化物高温超导 体在进入超导态后热导有所上升，出现极大值后再下降，而MgB2和MgCNi3 则单调下降. 由Wiedemann-Fra关键词：热导率超导体2}')" href="#">MgB₂3')" href="#">MgCNi₃

The thermal/electronic transport properties of new superconductor MgB2 and MgCNi3

The temperature dependence of thermal conductivity and electronic conductivity in superconductor MgB₂, MgCNi₃ and Bi₂Sr_{2Ca0.9Ce0.1Cu2O8+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.}