SPECIFIC-HEAT OF A ONE-DIMENSIONAL CARBON PHASE SYNTHESIZED BY CONDENSATION OF HIGH-TEMPERATURE CARBON GAS

We report on the specific heat, C(T), measurements in the temperature ranges 4.5 K < T < 30 K and 130 K < T < 730 K of a one-dimensional car bon crystal phase synthesized by condensation of high-temperature carb on gas. Even at the lowest achieved temperatures, the measured C(T) de pendence, to the first approximation, is close to the linear dependenc e over the wide temperature range from 15 K to 30 K. For the adequate description of the measured low-temperature C(T) dependence, the chain like crystal structure of the material has been considered, and the mo del of specific heat for quasi-one-dimensional crystals has been appli ed. By means of x-ray and high-temperature specific-heat measurements it has been found that the material is a metastable phase under the no rmal conditions, undergoing complicated irreversible transformations t o the amorphous state upon heating above T approximate to 350 K. [S016 3-1829(97)04629-8].