The Elastic Behaviour of the Amorphouse Carbon under High Pressure

By using the pules echo ultrasonic technique with 10 MHz, the ultrasonic velocities of the amorphous carbon and their pressure dependence have been measured in the pressure up to 1 GPa. We have calculated its second-, third- and combinations of forth-order elastic constants, and have researched its Gruneisen constant, Debye temperature, specific heat and state change under high pressure.