Results of differential scanning calorimetry (DSC) at different heating rates on Se0.7Ge0.2Sb0.1 glass are reported and discussed. From the heating rate dependence of glass transition, crystallization onset and peak crystallization temperatures values for the glass transition activation energy, Et, and the crystallization activation energy, Ec, were evaluated. The results are consistent with surface and one-dimensional crystallization for this glass. The calculated values of Et and Ec are 92±6 and 134±6 kJ/mol, respectively.

This work was partly supported by a Grant-in-Aid for Scientific Research from the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) and DAAD, Germany

Results of differential scanning calorimetry (DSC) under isothermal conditions on Se70Ge20Sb10 glass are reported and discussed. By using the Avrami equation the activation energy for crystal growth (EG) has been evaluated and the crystallization mechanism has been studied. The results indicate that the crystallization process is a one-dimensional growth. The calculated value of EG is 142.8 kJ mol-1 for Se70Ge20Sb10 chalcogenide glass

Results of differential scanning calorimetry (DSC) under isothermal conditions on Se70Ge20Sb10 glass are reported and discussed. By using the Avrami equation the activation energy for crystal growth (EG) has been evaluated and the crystallization mechanism has been studied. The results indicate that the crystallization process is a one-dimensional growth. The calculated value of EG is 142.8 kJ mol-1 for Se70Ge20Sb10 chalcogenide glass

Results of differential thermal analysis (DTA) under nonisothermal conditions on five chalcogenide glasses of the InxSe1 − x system (x = 0.05, 0.10, 0.15, 0.20 and 0.25 at.) are reported and discussed. The crystallization mechanism has been studied by using DTA, scanning electron microscopy (SEM) and X-ray diffraction. From the dependence of the glass transition temperature (Tg), the onset crystallization temperature (Tc) and the crystallization peak temperature (Tp) on the heating rate (α), the glass transition activation energy (Et) and the crystallization activation energy (Ec) were derived.

The calculated Et for InxSe1 − x varied between 246 and 309 kJ/mol. The results indicate that bulk crystallization with two-dimensional growth occurs for these glasses. The average activation energy of crystallization for InxSe1 − x varied between 105 and 125 kJ/mol. In0.10Se0.90 chalcogenide glass showed a minimum value of Ec as well as (Tc - Tg), which represents the thermal stability of the glass, indicating that this composition has a tendency towards crystallization more than the other compositions

Results of differential thermal analysis (DTA) under nonisothermal conditions on five chalcogenide glasses of the InxSe1 − x system (x = 0.05, 0.10, 0.15, 0.20 and 0.25 at.) are reported and discussed. The crystallization mechanism has been studied by using DTA, scanning electron microscopy (SEM) and X-ray diffraction. From the dependence of the glass transition temperature (Tg), the onset crystallization temperature (Tc) and the crystallization peak temperature (Tp) on the heating rate (α), the glass transition activation energy (Et) and the crystallization activation energy (Ec) were derived.

The calculated Et for InxSe1 − x varied between 246 and 309 kJ/mol. The results indicate that bulk crystallization with two-dimensional growth occurs for these glasses. The average activation energy of crystallization for InxSe1 − x varied between 105 and 125 kJ/mol. In0.10Se0.90 chalcogenide glass showed a minimum value of Ec as well as (Tc - Tg), which represents the thermal stability of the glass, indicating that this composition has a tendency towards crystallization more than the other compositions

Crystallization kinetics of the Bi10Se90−xInx glasses with x = 5, 10, and 20 at % have been studied under non-isothermal conditions. From the heating rate dependence of Tg and Tp, values of the activation energy for the glass transition (Et) and the activation energy for crystallization (Ec) are evaluated and their composition dependence discussed. DSC thermograms and X-ray diffractograms are useful in clarifying the role of In content on the crystallization phases and the electrical resistivity of these glasses. The results indicate that the crystallization mechanism involves several complex processes and that bulk crystallization with three-dimensional growth dominates over the other crystallization processes

Crystallization kinetics of the Bi10Se90−xInx glasses with x = 5, 10, and 20 at % have been studied under non-isothermal conditions. From the heating rate dependence of Tg and Tp, values of the activation energy for the glass transition (Et) and the activation energy for crystallization (Ec) are evaluated and their composition dependence discussed. DSC thermograms and X-ray diffractograms are useful in clarifying the role of In content on the crystallization phases and the electrical resistivity of these glasses. The results indicate that the crystallization mechanism involves several complex processes and that bulk crystallization with three-dimensional growth dominates over the other crystallization processes

From the X-ray diffraction data of Se1-xGex chalcogenide glasses (0<x<0.3) the radial distribution function (RDF) has been calculated. Using the RDF results the short- and medium-range order has been discussed. The results of the RDF indicate that the basic structure unit of the system is tetrahedral and the atoms are distributed according to the chain-crossing model and the edge- as well as corner-sharing tetrahedra. The amorphous and the crystalline phases have the same structure unit (for 0.2 at Ge). The germanium content does not have any influence on the basic structure unit. For x>0.1, the results indicate that the amorphous phase has medium-range order or topology order

Thin films of In0.10Se90 of thickness 200 Å are prepared by vacuum evaporation. The optical gaps (Eoptg) and the high-frequency dielectric constant (ɛɛ∞) are determined from the absorption spectrum of the In0.10Se0.90 films heat-treated at different temperatures. The effect of the temperature of heat treatment on the optical gap (Eoptg) and the high-frequency dielectric constant (ɛɛ∞) of the films is interpreted in terms of the density of state model of Mott and Davis and explained as being due to the saturation of bonds in the amorphous solid. It is shown that in the case of In0.10Se0.90 a transition from the amorphous to the crystalline state takes place at 373 K. The structural analysis of In0.10Se0.90 films by using XRD is reported.

Thin films of In0.10Se90 of thickness 200 Å are prepared by vacuum evaporation. The optical gaps (Eoptg) and the high-frequency dielectric constant (ɛɛ∞) are determined from the absorption spectrum of the In0.10Se0.90 films heat-treated at different temperatures. The effect of the temperature of heat treatment on the optical gap (Eoptg) and the high-frequency dielectric constant (ɛɛ∞) of the films is interpreted in terms of the density of state model of Mott and Davis and explained as being due to the saturation of bonds in the amorphous solid. It is shown that in the case of In0.10Se0.90 a transition from the amorphous to the crystalline state takes place at 373 K. The structural analysis of In0.10Se0.90 films by using XRD is reported.