Shock compressibility of C$_{70}$ fullerite at the pressure range 6 - 9 GPa*

Shock compressibility of C$_{70}$ fullerite was measured with the use of pulsed-periodical source of synchrotron radiation of the Institute of Nuclear Physics SB RAS. The starting C$_{70}$ specimens were prepared by high (1 GPa) hydrostatic pressure treatment and had a density of 1.65 g/cc, a diameter of 15 mm and a thickness of 2.5-3.5 mm. Specimens were loaded by impacts of metal plates (with a diameter of 16 mm) accelerated by high explosives. Synchrotron radiation technique was used to measure the parameters of the shock-compressed fullerite. This method of measurements is based on immediate visualization of X-T diagram of shock-wave processes by measuring a degree of attenuation of synchrotron radiation by an explored material during passage of a shock wave through this material. It was obtained that the experimental Hugoniot of C$_{70}$ fullerite in the explored pressure range (6.3-9.3 GPa) is allocated below the experimental Hugoniot of C$_{60}$ fullerite [V.V. Milyavskiy et al. Diamond and Rel. Mat. 14 (2005) 1920] on pressure - specific volume plane.