Compressibility of Solid C 60

Abstract

Room-temperature powder x-ray diffraction profiles have been obtained at hydrostatic pressures P = 0 and 1.2 gigapascals on the solid phase of cubic C₆₀ ("fullerite"). Within experimental error, the linear compressibility d(ln a)/dP is the same as the interlayer compressibility d(ln c)/dP of hexagonal graphite, consistent with van der Waals intermolecular bonding. The volume compressibility –d(ln V)/dP is 7.0 ± 1 x 10^-12 square centimeter per dyne, 3 and 40 times the values for graphite and diamond, respectively.