15 - Thermo-optical properties measurements in chalcogenide glasses using thermal relaxation and thermal lens methods (original) (raw)
Related papers
Journal of Non-crystalline Solids, 2004
In this work we determine the thermo-optical properties of two chalcogenide glasses (in mol%): 65 Ga 2 S 3 ; 30 La 2 S 3 ; 5 La 2 O 3 (Ga:La:S) and 72.5 Ga 2 S 3 ; 27.5 La 2 O 3 (Ga:La:S:O). The thermal relaxation calorimetry and the thermal lens technique were combined so that the samples specific heat, thermal diffusivity, thermal conductivity, and the temperature coefficient of the optical path length change could be measured. Our results indicate that changes in thermal diffusivity ($2.7 · 10 À3 cm 2 /s) and conductivity ($4.8 · 10 À3 W/K cm) observed when La 2 O 3 is added in the glass compounds are less than the error in the data.
Thermal–optical properties of Ga:La:S glasses measured by thermal lens technique
Journal of Non-crystalline Solids, 1999
In this work the quantitative theoretical treatment for two beam mode mismatched thermal lens spectrometry is applied to investigate the thermo-optical properties of chalcohalide (chalcolgenides and halides mixture) glasses. For the three kinds of glass studied the thermal diusivity varied between 2.5 and 2.7´10 À3 cm 2 s À1 . Using these results and supposing Dulong±Petit speci®c heats we estimated the thermal conductivity and temperature ratio of optical path length (ds/dT) and temperature coecient of refractive index (dn/dT). All samples had positive ds/dT ($3.3´10 À6 K À1 ) and negative dn/dT ($ À26´10 À6 K À1 ). The dierence between these parameters and the change of signal are consequences of the expansion coecient (13´10 À6 K À1 ) and refractive index (n $ 2.6) of chalcohalides. Ó 0022-3093/99/$ ± see front matter Ó 1999 Elsevier Science B.V. All rights reserved. PII: S 0 0 2 2 -3 0 9 3 ( 9 9 ) 0 0 0 6 6 -6
Thermal and optical properties of chalcohalide glass
Journal of Non-crystalline Solids, 2001
We report on the use of cw time-resolved Z-scan technique to investigate the thermal nonlinearity for the (mol%) 40% PbI 2 ± 30% Sb 2 S 3 ± 30% As 2 S 3 chalcohalide glass. Transient measurements were made with the sample ®xed at the peak position of the Z-scan curve, which is equivalent to the single beam thermal lens (TL) con®guration. The response time of the transient signal was used to obtain the sample thermal diusivity, D 1:3 Â 10 À3 cm 2 s À1 . The signal amplitude is proportional to the optical path length change with the heat deposited per unit volume, ds/dQ. The measurements were performed using a tunable Ti:sapphire laser in order to investigate the wavelength dependence in the range from 730 to 840 nm. This range is close to the glass Urbach tail, at k $ 700 nm, where ds/dT (or ds/dQ) increases. We observed that ds/dT increases by a factor of 9.3 when the wavelength decreases from 840 to 730 nm, while the absorption coecient increases by a factor of 1.7. Ó
Glass transition temperature T g is the most important parameter for characterization of any glassy material. T g may be considered as a measure of the onset of diffusion motion and the corresponding value of viscosity is found to be a constant (10 13 poise). Numerous studies have been done to correlate T g of chalcogenide glasses (sulfide, selenide and telluride glasses) with various physical and chemical parameters. In these studies, it is assumed that T g is mainly related to the heating rate, the average coordination number, the overall mean bond energy, and the relaxation process occurs from thermal history and ageing in the network. Several expressions of the relationship between T g and these various parameters have been reviewed in this work.
Journal of Applied Physics, 2007
The refractive index and the temperature coefficient of the optical path length change of tellurite (80TeO2:20Li2O) and chalcogenide glasses (72.5Ga2S3:27.5La2O3) were determined as a function of temperature (up to 150 °C) and wavelength (in the range between 454 and 632.8 nm). The tellurite glass exhibits the usual refractive index dispersion in the wavelength range analyzed, while anomalous refractive index dispersion was observed for the chalcogenide glass between 454 and 530 nm. The dispersion parameters were determined by means of the single-effective oscillator model. In addition, a strong dependence of the temperature coefficient of the optical path length on the photon energy and temperature was found for the chalcogenide glass. The latter was correlated to the shift of the optical band gap (or electronic edge) with temperature, which was interpreted by the electron-phonon interaction model.
Thermal relaxation method to determine the specific heat of optical glasses
Journal of Non-Crystalline Solids, 2002
In this work the thermal relaxation method is applied to determine the specific heat of the following optical glasses: undoped chalcohalides (As 2 S 3 and 40PbI 2 þ 30Sb 2 S 3 þ 30As 2 S 3); undoped and Nd 2 O 3 doped phosphate (38:66P 2 O 5 þ 40:22ZnO þ 21:12Na 2 O) and low silica calcium aluminosilicate (47:4CaO þ 41:5Al 2 O 3 þ 7:0SiO 2 þ 4:1MgO) glasses. For the latter the samples were melted both under vacuum and air conditions. Our results show that the specific heats of silica calcium aluminosilicate samples prepared under vacuum conditions were larger than that of the samples melted under air atmosphere. For chalcohalide glass sample (40PbI 2 þ 30Sb 2 S 3 þ 30As 2 S 3) the occurrence of a glass transition at 171°C was observed. These results indicate that this simple and low cost method is an useful tool to measure the specific heat of glasses as a function of the temperature.
Thermal conductivity of chalcogenide glasses measured by Raman spectroscopy
2018
We review the potential and limitations of a temperature-dependent Raman Scattering Technique (RST) as a nondestructive optical tool to investigate the thermal properties of bulk Chalcogenide Glasses (ChGs). Conventional thermal conductivity measurement techniques employed for bulk materials cannot be readily extended to thin films created from the parent bulk. This work summarizes the state of the art, and discusses the possibility to measure more accurately the thermal conductivity of bulk ChGs with micrometer resolution using RST. Using this information, we aim to extend the method to measure the thermal conductivity on thin films. While RST has been employed to evaluate the thermal conductivity data of 2D materials such as graphene, molybdenum disulfide, carbon nanotubes and silicon, it has not been used to effectively duplicate data on ChGs which have been measured by traditional measurement tools. The present work identifies and summarizes the limitations of using RST to measu...
Linear optical characterization of chalcogenide glasses
Optics Communications, 2004
A simple experimental method is used to obtain the evolution of both the refractive index and the linear absorption coefficient as a function of the optical wavelength in the near infrared range (from 900 up to 1700 nm with 10 nm resolution). Several chalcogenide glasses (As 2 S 3 , As 2 Se 3 , GeSe 4 ) are tested and the corresponding Cauchy coefficients are determined. Comparison of our results shows a good agreement with values available in the literature at some wavelength. Application of this method is used to estimate Cauchy coefficients of Ge 10 As 10 Se 80 for the first time to our best knowledge.
8 - Temperature and wavelength dependence of the thermo-optical properties
The refractive index and the temperature coefficient of the optical path length change of tellurite ͑80TeO 2 : 20Li 2 O͒ and chalcogenide glasses ͑72.5Ga 2 S 3 : 27.5La 2 O 3 ͒ were determined as a function of temperature ͑up to 150°C͒ and wavelength ͑in the range between 454 and 632.8 nm͒. The tellurite glass exhibits the usual refractive index dispersion in the wavelength range analyzed, while anomalous refractive index dispersion was observed for the chalcogenide glass between 454 and 530 nm. The dispersion parameters were determined by means of the single-effective oscillator model. In addition, a strong dependence of the temperature coefficient of the optical path length on the photon energy and temperature was found for the chalcogenide glass. The latter was correlated to the shift of the optical band gap ͑or electronic edge͒ with temperature, which was interpreted by the electron-phonon interaction model.
IJERT-Effect Of Thallium Additive On Heat Capacities Of In-Se Bulk Chalcogenide Glasses
International Journal of Engineering Research and Technology (IJERT), 2012
https://www.ijert.org/effect-of-thallium-additive-on-heat-capacities-of-in-se-bulk-chalcogenide-glasses https://www.ijert.org/research/effect-of-thallium-additive-on-heat-capacities-of-in-se-bulk-chalcogenide-glasses-IJERTV1IS9428.pdf Chalcogenide glasses are promising materials for optoelectronic device applications. Heat capacity of such materials is the essential physical parameter to estimate the energy/data storage capacity. In the present work, the effect of Tl incorporation on heat capacities ΔC pg , ΔC pc and ΔC pm of In 10 Se 90-x Tl x (7≤x≤15) and In 15 Se 85-x Tl x (2≤x≤10) bulk glasses have been investigated by analyzing the Differential scanning calorimetry (DSC) thermogram plots. Composition dependence of heat capacities of In-Se-Tl glassy systems have been obtained at the peaks of the glass transitions, crystallizations and melting temperatures (T g , T c and T m). It is found that the heat capacities of In 10 Se 90-x Tl x and In 15 Se 85-x Tl x glasses increases initially with the incorporation of thallium (up to x≤13 and x≤6) and reaches to maximum at x=13 and x=6 respectively beyond which it decreases. This behavior seems to follow the change in network connectivity and rigidity and may be explained with the help of chemical bond theory of solids. Further in these glassy materials, at the average coordination =2.46 (x=13) and = 2.42 (x=6) a sharp slope change is seen in the composition dependence of heat capacity of both the series which is attributed to the rigidity percolation threshold.