Study of Activation Energy of Crystallization and Growth Morphology of Ge25−x Se75 Sb x (x  = 12, 15, 18) Chalcogenide Glasses

2017 ◽  
Vol 376 (1) ◽  
pp. 1600185
Author(s):  
Naveen Tanwar ◽  
Vibhav K. Saraswat
2014 ◽  
Vol 8 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Anusaiya Kaswan ◽  
Vandana Kumari ◽  
Dinesh Patidar ◽  
Narendra Saxena ◽  
Kananbala Sharma

The kinetics of crystallization of Ge30-xSe70Sbx (x=15, 20, 25) chalcogenide glasses has been investigated using differential scanning calorimetery at different heating rates under non-isothermal conditions. The kinetic analysis of crystallization has been discussed using different theoretical approaches such as Ozawa model, Augis and Bennet model, Matusita model and Gao-Wang model. It is evident from this study that the activation energy of crystallization Ec is composition dependent. The activation energy decreases with increasing Sb content due to the increasing of rate of crystallization. The minimum value of the frequency factor Ko, which is defined as the number of attempts made by the nuclei per second to overcome the energy barrier, confirms the fact that glass is more stable. It has been found that Ge15Se70Sb15 glass is more stable compared to the other compositions.


Author(s):  
А. А. Горват ◽  
В. М. Кришеник ◽  
А. Е. Кріштофорій ◽  
В. В. Мінькович ◽  
О. А. Молнар

1982 ◽  
Vol 28 (2) ◽  
pp. 137-144 ◽  
Author(s):  
W. Fernengel ◽  
H. Kronm�ller ◽  
M. Rapp ◽  
Y. He

2017 ◽  
Vol 898 ◽  
pp. 657-665
Author(s):  
Dao Zhang ◽  
Wang Shu Lu ◽  
Xiao Yan Wang ◽  
Sen Yang

The non-isothermal crystallization kinetics of Mg61Zn35Ca4 glassy alloy prepared via melt-spinning were studied by using isoconversion method. The crystalline characterization of Mg61Zn35Ca4 was examined by X-ray diffraction. Different scanning calorimeter was used to investigate the non-isothermal crystallization kinetics at different heating rates (3-60 K/min). The calculated value of Avrami exponent obtained by Matusita method indicated that the crystalline transformation for Mg61Zn35Ca4 is a complex process of nucleation and growth. The Kissinger-Akahira-Sunose method was used to investigate the activation energy. The activation energy of crystallization varies with the extent of crystallization and hence with temperature. The Sestak-Berggren model was used to describe the non-isothermal crystallization kinetics.


Author(s):  
Shiveom Srivastava ◽  
S. K. Srivastava ◽  
Krishna K. Srivastava ◽  
Narayan P. Srivastava

Electrical conductivity of Ge10 Se90-x Bix (x=0,2,4,6,8,10) glassy systems prepared by melt quenching technique has been studied at different temperature in bulk form through I-V characteristic curves. It has been observed that the electrical conductivity increases as the Bi concentration increases up to 4 atomic weight percentages and on further addition of Bi it reduces. The variation in electrical conductivity with Bi concentration is attributed to the Se-Bi bond concentration. Using the Arrhenius equation of conductivity, the activation energy of conduction is evaluated. The effect of Bi concentration on activation energy has also been studied. It is quite evident from results that Poole-Frankel and Rechardson-Schottky conduction mechanism hold good for conduction in these glasses.


2012 ◽  
Vol 188 ◽  
pp. 21-26
Author(s):  
Aurel Raduta ◽  
Mircea Nicoară ◽  
Cosmin Locovei

A research program has been completed in order to analyze structural changes during heating of amorphous alloys belonging to Fe-Ni-P system. Special attention has been given to thermodynamics and mechanism of crystallization, to determine some aspects of development for crystalline phases. Experimental material used to determine characteristics of crystallization consisted in long ribbons, 30 thick and 18 mm wide, fabricated by mean of “Planar Flow casting” as amorphous Fe42Ni38P16B4alloy. Differential Thermal Analysis (DTA) and X-rays diffraction have been used to determine crystallization temperature of this alloy. Curves of differential thermal analysis for heating rates ranging between 1°C/minute and 20 °C/minute have been used to determine activation energy of crystallization.


2010 ◽  
Vol 105-106 ◽  
pp. 743-745
Author(s):  
Li Jie Qu ◽  
Bin Li ◽  
Jing Wang ◽  
Yue Mei Gu

Glass-ceramics with desired microstructures and properties are controlled by nucleation and crystallization. The nucleation and crystallization of glass, which include the nucleation, crystal growth rates and the activation energy, are important in understanding the stability of glass in practical applications. The activation energy of crystallization (E) plays an important role in determining the utility of glass ceramic. The amorphous to crystalline transformation in glass can be investigated by isothermal and non-isothermal method which is differential scanning calorimetric (DSC). In the isothermal method, the sample is measured as a function of time, while in the non-isothermal method the sample is recorded as a function of temperature. An advantage of the non-isothermal method is the possibility of reaching a test temperature instantaneously and during the time, which system needs to stabilize. However, the isothermal method does not have this advantage. In the present work, this technique was used to calculate the activation energy of CaO-Al2O3-SiO2-CeO2 glass-ceramics. DSC technique can be used as to determine the optimum heat treatment temperature. The advantage of the DSC technique in study of glass-ceramics is that it requires much less time.


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