研究目的
To describe the enthalpy relaxation processes in the (GeSe2)y(Sb2Se3)1-y chalcogenide glasses and correlate the activation energies of the relaxation movements and viscous flow via the fragility concept.
研究成果
The study concluded that increased presence of germanium (GeSe2 units) leads to a gradual exponential increase of the glass transition temperature and linear decreases of the activation energy for the structural relaxation movements. The activation energy of structural relaxation was found to be similar to the activation energy of viscous flow. Non-exponentiality and non-linearity kinetic features were found to be invariant with glass composition.
研究不足
The study was limited to the compositional range of y = 0.3–0.9 for (GeSe2)y(Sb2Se3)1-y glasses. The conclusions for the (GeSe2)0.3(Sb2Se3)0.7 composition were noted to be less certain due to higher noise in the data.
1:Experimental Design and Method Selection:
The study employed differential scanning calorimetry (DSC) and Raman spectroscopy to investigate enthalpy relaxation processes. The Tool-Narayanaswamy-Moynihan (TNM) model was used for phenomenological description of enthalpy relaxation.
2:Sample Selection and Data Sources:
(GeSe2)y(Sb2Se3)1-y glasses (y =
3:3–9) were prepared from pure elements using the standard melt-quenching technique. List of Experimental Equipment and Materials:
A Bruker AXS diffractometer D8 Advance for X-ray diffraction, a DXR2 Raman microscope for Raman spectroscopy, and a Q2000 DSC (TA Instruments) for calorimetric studies.
4:Experimental Procedures and Operational Workflow:
DSC relaxation experiments were performed using constant ratio (CR) and constant heating rate (CHR) cycles in the glass transition region. Raman spectroscopy was used to provide structural information.
5:Data Analysis Methods:
The kinetics of the structural relaxation was described in terms of the TNM model. Raman spectra were deconvoluted to analyze structural arrangements.
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