We present a model equation of state for C 60 based on a variational series mean spherical approximation for a double Yukawa fluid. This allows us to investigate the liquid-vapour coexistence curve and calculate the thermodynamic properties of liquid C 60 . The comparisons with computer simulation results, based on the Girifalco potential, suggest the importance of treating the attractive tail of the potential accurately. The estimated critical parameters, T c = 1943 K, ρ c = 0.477 nm −3 and P c = 34.2 bar, are in good agreement with Gibbs ensemble Monte Carlo simulation predictions. The results are discussed, making reference to previous studies.

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The utility of ion-assisted deposition is investigated to explore the possibility of counteracting the deficiency of back-reflected current of Ar neutrals in the case of lighter elements such as Al. A range of energetically ion bombarded Fe∕Al multilayers sputtered with applied surface bias of 0, −200, or −400V were deposited onto Si(111) substrates in an argon atmosphere of 4mTorr using a computer controlled dc magnetron sputtering system. Grazing incidence reflectivity and rocking curve scans by synchrotron x rays of wavelength of 1.38Å were used to investigate the structures of the interfaces produced. Substantial evidence has been gathered to suggest the gradual suppression of interfacial mixing and reduction in interfacial roughness with increases of applied bias. The densification of the Al microstructure was noticeable and may be a consequence of resputtering attributable to the induced ion bombardment. The average interfacial roughnesses were calculated for the 0, −200, and −400V samples to be 7±0.5, 6±0.5, and 5±0.5Å respectfully demonstrating a 30% improvement in interface quality. Data from rocking curve scans point to improved long-range correlated roughness in energetically deposited samples. The computational code based on the recursive algorithm developed by Parratt [Phys. Rev. 95, 359 (1954)] was successful in the simulation of the specular reflectivity curves.