Enthalpy relaxation and structure in vitreous Ge15Te85

Very long physical ageing in inorganic polymers exemplified by the GexSe1−x vitreous system

“…Indeed it is also well known that ageing leads in addition to the increase of the relaxation peak and to an increase in the apparent glass transition temperature. The simultaneous variations of the peak surface and the peak temperature are at the origin of the peak shift method [19] used by several researchers to describe quantitatively the relaxation kinetics in glassy polymers [20][21][22][23]. From the second series of measurements, we have determined the values of the glass transition temperatures taken at the Table 1.…”

“…This remains true for the study performed by Lucas et al [28] on the same vitreous system with the highest composition of Ge. This explains the success of the alloys average coordination number concept as defined by Phillips [29], which is used to describe and to compare the behaviours obtained on different families of alloys as Ge-Te [22,30], Ge-Se and As-Se [31]. Although our experiments do not permit one to know exactly when the double peaks occur during ageing, it is clear it needs a long-time ageing at low annealing temperature to get them (T g ÀT a at the beginning of our experiments were close to 40, 70 and 110 1C for samples with 4, 8 and 12 at% of Ge, respectively).…”

Structural relaxation due to sub-Tg annealing of Se98In1.5Sn0.5 chalcogenide glass

“…It is well known [1][2][3] that amorphous chalcogenide glasses synthesized from the liquid state are intrinsically in a thermodynamic non-equilibrium state. This is because the glass transition occurs when a liquid becomes highly viscous, as the temperature decreases, and cannot relax fast enough to reach the state of thermal equilibrium.…”

Recovery response of optical stopping effect on P2As20S78 and Sn1As20S79 film waveguide

“…However, As 20 S 80 , with a low coordination number (∼2.2), has been referred to as a soft glass semiconductor with high concentration of bond defect and a number of sublevels in the forbidden band. [12][13][14] Optical stopping experiment with the photo-optical effect in As 20 S 80 film waveguide and stripe waveguide via using the sub-level electron transition to absorb the signal light was reported, which does not occur in As 40 S 60 . 15 This effect is expected to find its application in the development of the new waveguide devices.…”