Transport properties of fullerite samples

We have studied the transport properties of hard C-60 and hard C-70 fulleri tes. The samples from pristine C-60 and C-70 powder were synthesised at hig h pressure and high temperatures. Their electrical resistivity at room temp erature is 35 mu Omegam and 85 mu Omegam, respectively, and is weakly depen dent on temperature. X-ray diffraction show lack of the long range crystall ine order. The room temperature value of the thermal conductivity is 2Wm(-1 )K(-1) for both samples. Thermal conductivity of hard C-70 fullerite increa ses with temperature and becomes almost temperature independent in the temp erature range 10 K-30 K. Contrary, thermal conductivity of hard C-60 fuller ite increases with temperature in whole investigated temperature range, whi ch is a consequence of the competing influences of the higher conductivity of crystalline regions and of the thermal resistance which arises at the ju nctions between amorphous and crystalline regions.