Crystallization kinetics of chalcogenide glasses doped with Sb (original) (raw)
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Crystallization kinetics of Ge 20 Te 80 chalcogenide glasses doped with Sb
Physica B, 2005
A study of kinetics of non-isothermal crystallization process for Ge 20Àx Te 80 Sb x ðx ¼ 0; 3; 4; 5Þ system was reported and interpreted in this work by using Matusita's model. From the differential scanning calorimetry (DSC) traces obtained under dynamic conditions, the activation energy of growth process and values of n and m which are numerical factors depending on crystallization mechanisms are evaluated. The validity of Matusita's model was ascertained by comparison with the results obtained by application of two well-known methods which are Ozawa and Kissinger ones.
Non-isothermal crystallization kinetics of Sb10Ge10Se80 chalcogenide glass
Fizika A
A differential scanning calorimetry technique was used to study the crystallization kinetics of Sb10Ge10Se80 chalcogenide glass under non-isothermal conditions. The crystallization parameters such as the order parameter (n), the frequency factor (k0), the activation energy of crystallization (Ec), the activation energy of glass transition (Eg) and the activation energy of nucleation (En) were determined. The value of Ec was deduced by means of six methods and the average value was found to be equal to (76.10 ±11.10) kJmol-1. The most suitable method for crystallization kinetic studies was the Augis-Bennett approximated method at different heating rates, while the method of Coats-Redfern-Sestak was the most suitable one at constant heating rate. The results have been discussed on the basis of theoretical principles.
Thermochimica Acta, 2005
The crystallization kinetics of Sb 9.1 Te 20.1 Se 70.8 chalcogenide glass have been studied by differential scanning calorimetry (DSC). The effective activation energy of crystallization has been evaluated on the basis of the Kissinger equation and the method of Matusita et al. The Sestak-Berggren model has been used for the description of DSC crystallization data as it provides the best fit to the experimental results. It has been found that the Johnson-Mehl-Avrami model could be applied at very high rates of heating.
Crystallization kinetics of Ge17. 5Te82. 5 chalcogenide glass
… status solidi (a), 2003
The crystallization kinetics of the Ge 17.5 Te 82.5 chalcogenide glass were obtained by using differential scanning calorimetry (DSC) under non-isothermal conditions. The fraction of crystallized material, calculated using the partial area analysis, revealed that the crystallization process of the Ge 17.5 Te 82.5 glass was twoand three-dimensional. The crystallization of the Ge 17.5 Te 82.5 glass was confirmed by X-ray investigation of the as-prepared and annealed powder. The glass transition activation energy (E G) and the crystallization activation energy (E c) were calculated from the DSC thermograms using different methods.
Kinetics study of non-isothermal crystallization in Se0.7Ge0.2Sb0.1 chalcogenide glass
Journal of Non-Crystalline Solids, 1991
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, E t, and the crystallization activation energy, E~, were evaluated. The results are consistent with surface and one-dimensional crystallization for this glass. The calculated values of E t and E~ are 92_+6 and 134 + 6 kJ/mol, respectively.
Chalcogenide glasses based on Ge-Te-Sb are used in the technology of phase change optical memories. Non-isothermal crystallization for Ge 15.5-x Te 84.5 Sb x (0.5 <x< 1.5) investigated by differential scanning calorimetry (DSC) shows two glass transition temperatures followed by two crystallization peaks and melting point at 385°C . The activation energy of crystallization has been calculated in the frame of three models: Matusita, Kissinger and Ozawa. The particularity of every model is analysed.
Journal of Non-Crystalline Solids, 2009
The glass transition behavior and crystallization kinetics of Se 58 Ge 42Àx Pb x (x = 9, 12) have been investigated using Differential Scanning Calorimetry (DSC) at five different heating rates under non-isothermal conditions. It has been observed that these glassy systems exhibit single glass transition and double crystallization on heating. The XRD pattern revealed that the considered glasses get crystallized into GeSe 2 and PbSe/Se phases after annealing at 633-643 K for 2 h. The GeSe 2 and Se phases were found to crystallize in monoclinic structure while, PbSe phase crystallizes in cubic structure. Besides this, a mixed phase was also observed in DSC thermograms after annealing. The kinetic studies include determination of various parameters such as Avrami exponent (n), frequency factor (K o), dimensionality of growth (m), the activation energy for glass transition (E t) and for crystallization (E c). The values of E t increases while that of E c decreases after annealing. Also, dimensionality of growth decreases to one dimension from two and three dimensions after annealing.
Study of transition kinetics of Se80Te20−xInx chalcogenide glasses
Indian Journal of Physics, 2019
Chalcogenide glasses with the chemical formula Se 80 Te 20-x In x (x = 5, 10 and 15) were prepared using the melt quenching method. The amorphous nature of the prepared samples was checked by X-ray diffraction analysis. The thermal behavior was investigated by using differential scanning calorimetry at different heating rates, 5, 10, 15 and 20°C/min. Lasocka relation was used to study the heating rate dependence of the glass and crystallization temperatures. Kissinger and Mahadevan models were used to determine the glass and crystallization activation energies. The time dependence of the ac conductivity at 1 kHz performed at different annealing temperatures, 75, 80, 85 and 90°C, was used to calculate Avrami exponent. The frequency factor was determined from the temperature dependence of the rate constant.