Structural studies of tungstate-tellurite glasses by raman spectroscopy and differential scanning calorimetry

1995 ◽  
Vol 56 (1) ◽  
pp. 141-150 ◽  
Author(s):  
I. Shaltout ◽  
Yi Tang ◽  
R. Braunstein ◽  
A.M. Abu-Elazm
Author(s):  
B. Hauke ◽  
E. R. Barney ◽  
E. Pakhomenko ◽  
M. Jesuit ◽  
M. Packard ◽  
...  

Tellurite glasses, made from the conditional glass former TeO2, show potential for use in optical applications. Alkali and alkaline earth tellurite glasses, along with single component, rapidly cooled, TeO2 are reported and studied here. Thermal properties of boron, potassium, lithium, sodium, rubidium, cesium, barium, and strontium tellurites were obtained via differential scanning calorimetry and related to structural changes observed using Raman spectroscopy. Additionally, coordination numbers of barium and strontium tellurites versus amount of modifier are also calculated. By understanding the thermal properties and coordination numbers of alkali and alkaline earth tellurites, the goal is to better elucidate the structure of amorphous TeO2.


2010 ◽  
Vol 24 (06) ◽  
pp. 527-537
Author(s):  
E. B. ARAÚJO ◽  
E. IDALGO ◽  
A. P. A. MORAES ◽  
A. G. SOUZA FILHO ◽  
J. MENDES FILHO

Tellurite glasses were prepared with identical 20 Li 2 O -80 TeO 2 nominal compositions but with different thermal histories. Differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Raman spectroscopy techniques were used to understand the effects of the thermal histories on the thermal and structural properties of these glasses. It was observed that investigated properties depend strongly on the thermal histories. DSC results suggested that annealing immediately after quenching at temperatures around the glass transition temperature (Tg) and for longer times is favorable for producing local ordered regions in the glass without necessarily increasing the number of nuclei. XRD results revealed the crystallization of the γ- TeO 2, α- TeO 2 and α- Li 2 Te 2 O 5 phases in both studied glasses. Raman spectroscopy revealed the mestastable character of the γ- TeO 2 crystalline phase, while the α- TeO 2 and α- Li 2 Te 2 O 5 crystalline phases persisted up to the final stages of the in-situ crystallization.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Richard Jumeau ◽  
Patrice Bourson ◽  
Michel Ferriol ◽  
François Lahure ◽  
Marc Ponçot ◽  
...  

The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.


2016 ◽  
Vol 3 ◽  
pp. 47-50
Author(s):  
Birgit Neitzel ◽  
Florian Aschermayer ◽  
Milan Kracalik ◽  
Sabine Hild

Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC) were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests.


2021 ◽  
pp. 2150407
Author(s):  
S. I. Ibrahimova

The crystal structure and thermal properties of the [Formula: see text] compound have been investigated. Structural studies were performed by X-ray diffraction at room temperature. The crystal structure of this compound was found to correspond to the hexagonal symmetry of the space group P61. Thermal properties were studied using a differential scanning calorimetry (DSC). It was found in the temperature range [Formula: see text] that thermal effects occur at temperatures [Formula: see text] and [Formula: see text]. The thermodynamic parameters of these effects are calculated.


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