Secondary relaxation in the glass-transition regime ofortho-terphenyl observed by incoherent neutron scattering

Abstract
We report on incoherent-neutron-scattering measurements in the supercooled regime of the van der Waals liquid ortho-terphenyl. A secondary localized relaxational process on the picosecond time scale is found. In accordance with mode-coupling theories of the glass transition, the relaxational dynamics around a critical temperature Tc decomposes into two time regimes.