Neutron-scattering study of low-energy excitations in some organic glass formers

Thermal and relaxational properties of glass-forming material, 3,3-dimethyl-1-butanol

“…It is evident that the heat capacity of the glassy state is always larger than that of the crystalline state and that there exists a broad maximum around T = 30 K. This type of anomaly is often, encountered in glassy materials and is related to the existence of the Boson peak in the density of states. In fact, neutron inelastic scattering experiment of this material [19] clearly detected the Boson peaks centered at 2.31 meV and 3.50, meV. These energies correspond to 27 K and 41 K, respectively, in terms of thermal energy kT, where k is the Boltzmann constant.…”

“…The Polish authors of the present paper have developed adiabatic calorimetry, neutron inelastic scattering and dielectric relaxation studies for 3,3-dimethyl-1-butanol as a part of the large project for glass-formers having various values of fragility [14][15][16][17]. The substance has been chosen as a suitable candidate for our investigations because we expected it will exhibit a low fragility as the isomer of 2,3-dimethyl-2-butanol [18].…”

“…The substance has been chosen as a suitable candidate for our investigations because we expected it will exhibit a low fragility as the isomer of 2,3-dimethyl-2-butanol [18]. The aim of the present paper is to determine the thermodynamic quantities of the crystalline and the glassy states of this material and to compare the calorimetric knowledge with the results of the dielectric relaxation experiments and the neutron inelastic scattering [19].…”

Thermodynamic properties of chiral liquid crystalline material (S)-4-(2-methylbutyl)-4′-cyanobiphenyl (5∗CB)

“…Later, in neutron scattering experiments, different diffraction patterns were observed for three solids, i.e. glass of the cholesteric phase and the two crystalline phases [8]. Incoherent inelastic neutron scattering (IINS) measurements were also carried out, and the vibrational density of states (DOS) of three phases was investigated [8].…”

“…glass of the cholesteric phase and the two crystalline phases [8]. Incoherent inelastic neutron scattering (IINS) measurements were also carried out, and the vibrational density of states (DOS) of three phases was investigated [8]. From the DOS obtained, crossover of the Gibbs free energy between the two crystalline phases has been expected, as well as the existence of a phase transition below T = 200 K.…”