No abstract

Temperature and wavelength dependence of the thermo-optical properties of tellurite and chalcogenide glasses

No abstract

The aim of the present work is to attempt to make a number of different glasses, based on tellurite as the principal former, which contain substantial quantities of zinc oxide up to 40 mol % ZnO. To study the longitudinal elastic properties, measurements have been made of the velocity of the longitudinal ultrasonic waves propagated through the prepared glasses. The results indicate that the longitudinal elastic constants depend strongly upon the composition of the prepared glasses. A detailed qualitative interpretation of the increase in the modulus is made. Information about the structure of the glass can be deduced after calculating the number of network bonds per unit volume and the crosslink density. The role of the halogen inside the glass network is discussed.

A series of binary tellurite-phosphate glasses in the form [TeO2]0.81[P2O5]0.19 doped with different rare-earth oxides were prepared. The rare-earth oxides were: La2O3, CeO2, Pr2O3, Nd2O3, Sm2O3, and Yb2O3. The optical absorption coefficient and infrared spectra were measured in the ranges 200–900 nm and 200–1000 cm−1, respectively. It is found that the fundamental absorption edge depends upon the kind of the dopant cation. The infrared spectra of these doped glasses indicate that the rare-earth oxides are connected to the chains of TeO4.

No abstract

No abstract

The ionizing radiation shielding parameters of (90-y)TeO2-yV2O3-5CaO-5Na2O (TVCN): y = 5–20 mol% semiconductor glasses were investigated. The avarage track lengths of photons with different energies (0.015- 15 MeV) in the TVCN-glasses were simulated via MCNP-5 code, then the corresponding LAC were computed. Based on LAC values, the MACs were calculated and compared with values which obtained via XCOM software. The highest LAC achieved for low energy (0.015 MeV) and reduced from 199.549 to 169.891 cm− 1, while the lowest values achieved for gamma photon with higher energies and reduced from 0.188 to 0.161 cm− 1 with replacment of TeO2 compound by V2O5. The highest (I/Io) achieved for TVCN20 glasses and decreased from 0.703 to 0.172., while the lowest (I/Io) performed for TVCN5 glasses and decreased from 0.680 to 0.145 for glasses thickness varied between 1 and 5 cm. The thinner HVL was achieved for TVCN5 and increases from 0.003 to 3.684 cm, while the thicker HVL was achieved for TVCN20 and increases from 0.004 to 4.293 cm. The highest dose rate was recorded in the presence of theTVCN20 glasses and varied between 5.680 and 23.210 µSv/hr, while the lowest dose rate recorded in the presence of the TVCN5 glasses and varied between 4.807 and 22.448 µSv/hr for glass thickness varied in range between 1–5 cm. The highest values of the Zeff was recorded for glasses TVCN5 and varied between 21.209 and 50.402, while the lowest Zeff achieved for TVCN20 and varied between 18.489 and 40.479. The calculated buildup factors (EBF and EABF) reach maximum values for glasses TVCN5 while the lowest EBF and EABF achieved for glasses TVCN20. Therefore, the glasses TVCN5 have a higher ability to attenuate the incident gamma photons. Thus, the TVCN-glasses can be applied in various radiation shielding applications in medical area.