Bulk metallic glasses (BMGs) have received a great deal of attention due to scientific and technological interest ever since the first successful synthesis of an amorphous phase in the Au–Si system in 1960 (Klement et al., 1960). There has been a lot of interest to identify parameters to assess the glass forming ability (GFA) of various alloy systems and compositions. A great deal of scientific...

For nonpolymeric supercooled liquids, the empirical correlation m = 56Tg DeltaCp(Tg)/DeltaHm provides a reliable means of correlating dynamic and thermodynamic variables. The dynamics are characterized by the fragility or steepness index m and the glass transition temperature Tg, while thermodynamics enter in terms of the heat capacity step DeltaCp at Tg and the melting enthalpy DeltaHm. The co...

We report a molecular dynamics investigation of the glass transition temperature in selenium at pressures ranging from 0 to 6 GPa as a function of the quench rate, Qr . For moderate pressures the specific volume of the glass depends strongly on the quench rate, whereas the specific enthalpy varies only little. We find for both volume and energy a linear dependence on the quench-rate-dependent g...

Via analysis of spatiotemporal arrangements of atoms based on their dynamics in supercooled liquid and glassy states of a 2D monatomic system with a double-well Lennard-Jones-Gauss (LJG) interaction potential, we find a new scenario of dynamical heterogeneity. Atoms with the same or very close mobility have a tendency to aggregate into clusters. The number of atoms with high mobility (and size ...

The translational dynamics of the low molecular weight glass-former tris(naphthylbenzene) have been studied on the length scale of a few nanometers at the glass transition temperature Tg. Neutron reflectivity was used to measure isotopic interdiffusion of multilayer samples created by physical vapor deposition. Deposition with the substrate held at Tg-6 K allows observation of dynamics characte...

Cyclic olefin copolymers comprise a new class of polymeric materials showing properties of high glass-transition temperature, optical clarity, low shrinkage, low moisture absorption, and low birefringence. There are several types of cyclic olefin copolymers based on different types of cyclic monomers and polymerization methods. In this work, we have analyzed the chemical structure of the curren...

We employ dielectric spectroscopy to monitor the relaxation dynamics and crystallization kinetics of the Biclotymol antiseptic in its amorphous phase. The glass transition temperature of the material as determined by dielectric spectroscopy is Tg = 290 ± 1K. The primary (α) relaxation dynamics is observed to follow a Vogel-Fulcher-Tammann temperature dependence, with a kinetic fragility index m...

X-ray reflectivity measurements of the glass transition in thin polystyrene films supported on Si substrates were performed at slow cooling rates ranging from 0.62 to 0.01 (°)C/min. At a cooling rate of 0.14 (°)C/min, a depression in the glass transition temperature Tg was clearly observed with decreasing thickness. However, at a cooling rate of 0.62 (°)C/min, only a slight decrease in Tg for a...

We prepared numbers of GeAsSe glasses and investigated their thermal stability and optical properties in order to search the best glasses with relatively high glass transition temperature Tg, strong structural stability, low optical loss and high optical nonlinearity. Through our systematical measurements, we concluded that the glasses with a mean coordination number around 2.45-2.5 are the bes...

§ Laboratoire GCR-CNRS URA 769 Université Pierre et Marie Curie, Tour 22, Boite 142 4, Place Jussieu, 75252 Paris Cedex 05, France ¶ Instituto de Fisica, Universidad Nacional Autonoma de México Apartado Postal 20-364, 01000 México DF, México (February 1, 2008) We give in this letter a set of general rules which allow the prediction of the value of the glass transition temperature Tg in network ...