Neutron-scattering study of low-energy excitations in triphenyl phosphite

The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results – the incoherent dynamic structure factor S(2θ,ω) and the density of states G(ω) – were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed.