Author/Authors :
Moreno، نويسنده , , A.J. and Alegr??a، نويسنده , , A. and Colmenero، نويسنده , , J. and Mukhopadhyay، نويسنده , , R. and Frick، نويسنده , , B.، نويسنده ,
Abstract :
The methyl group rotational tunnelling in poly(vinyl acetate) (PVAc) has been analysed by means of neutron scattering covering a range of tunnelling frequencies from 0.5 μeV to the free rotor line at 0.65 meV. The measured spectra show an apparently quasielastic broadening that has been interpreted in terms of a distribution of tunnelling frequencies. The results obtained in present experiments support those obtained previously from the analysis of the tunnelling spectrum in a smaller width window in combination with measurements in the classical hopping regime.
