Transport properties of fullerite samples

摘要

We have studied the transport properties of hard C_(60) and hard C_(70) fullerites. The samples from pristine C_(60) and C_(70) powder were synthesised at high pressure and high temperatures. Their electrical resistivity at room temperature is 35#mu# #OMEGA#m and 85 #mu##OMEGA#m, respectively, and is weakly dependent on temperature. X-ray diffraction show lack of the long range crystalline order. The room temperature value of the thermal conductivity is 2Wm~(-1)K~(-1) for both samples. Thermal conductivity of hard C_(70) fullerite increases with temperature and becomes almost temperature independent in the temperature range 10 K-30 K. Contrary, thermal conductivity of hard C_(60) fullerite increases with temperature in whole investigated temperature range, which is a consequence of the competing influences of the higher conductivity of crystalline regions and of the thermal resistance which arises at the junctions between amorphous and crystalline regions.