ELASTIC AND DISSIPATIVE PROPERTIES OF SOLID C-60

Elastic and dissipative properties of solid C-60 in the face centered cubic (fcc) and high pressure induced phases were measured on tile sam e specimens. The high pressure phase was synthesized in our experiment s by the thermobaric treatment of specimens at temperature of 350 degr ees C and under pressure of 2 GPa. The structure investigations reveal ed the origination of tile chemical bonding between C-60 molecules in that phase. The measurements of attenuation and velocities of longitud inal and transverse sound waves were carried out in the temperature ra nge from 4.2 to 330 K at tile frequencies of 5 and 10 MIIz by echo pul se and high frequency resonance methods. It was found that the values of elastic moduli of the new phase, measured at room temperature, appe ared two times higher and their temperature dependences two times weak er than corresponding ones of the pristine C-60. The internal friction spectrum of fee phase differs significantly from that of hpp phase. T he phenomena observed are discussed in terms of model taking into acco unt the formation of polymer chains in thp structure of the new pressu re-induced phase of solid C-60.