Lattice dynamics of a rotor-stator molecular crystal: Fullerene-cubane C-60 center dot C8H8

Article

关键词: X-RAY-SCATTERING;    NEUTRON-SCATTERING;    SOLID C-60;    PHASE-TRANSITIONS;    DIFFUSE-SCATTERING;    COCRYSTALS;    DISORDER;    POLYMER;    C60;    O-2;   

DOI  :  10.1103/PhysRevB.82.195413

来源: SCIE

【 摘 要 】

The dynamics of fullerene-cubane (C-60 center dot C8H8) cocrystal is studied combining experimental [x-ray diffuse scattering, quasielastic and inelastic neutron scattering (INS)] and simulation (molecular dynamics) investigations. Neutron scattering gives direct evidence of the free rotation of fullerenes and of the libration of cubanes in the high-temperature phase, validating the rotor-stator description of this molecular system. X-ray diffuse scattering shows that orientational disorder survives the order/disorder transition in the low-temperature phase, although the loss of fullerene isotropic rotational diffusion is featured by the appearance of a 2.2 meV mode in the INS spectra. The coupling between INS and simulations allows identifying a degeneracy lift of the cubane librations in the low temperature phase, which is used as a tool for probing the environment of cubane in this phase and for getting further insights into the phase transition mechanism.

【 授权许可】

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