Electric resistance of the ZrC-C system specimens prepared by chemical gaseous deposition

Results of the investigation on electric resistivity of the ZrC-C system pyrolytic specimens in the range of 78-300 K are presented. The results have been obtained using the method of chemical vapor deposition from ZrCl4+CH4+He mixture at 1500 deg C on the substrate of a highly dense pyrographite. It is shown that with the free carbon content increase carbide grain configuration changes from columnar to fine-dispersed. The electric resistivity of the ZrC-C system carbon phase obtained by the method of chemical vapor deposition is considerably higher than that of the corresponding phase in carbidographites that results in a more complex dependence of the investigated system on the free carbon content. A great difference in the electric resistivity of carbide and carbon phases defines the rho concentration dependence. The temperature dependence of the electric resistivity of ZrC-C system specimens in the range of 78-300 K is practically linear