LOW-ENERGY EXCITATIONS IN SIMPLE MOLECULAR GLASSES

We have studied the low energy excitations in the glassy simple hydroc arbon molecules. For all of the samples studied, non-Debye heat capaci ty was observed below 30 K and a clear boson peak appeared at 2-3 meV in their inelastic neutron scattering spectra. These data provided the absolute value of the excess density of states G(LEE)(w) associated w ith the low energy excitations. The G(LEE)(w) was analyzed in terms of the soft potential model. The magnitude of the low energy excitations and the boson peak energy were both dependent on the molecular weight and molecular structure.