Newly developed BGO glasses: Synthesis,optical and nuclear radiation shielding properties

In this research paper, we studied the optical and nuclear shielding efficiency of newly developed BGO glasses with the following compositions (in wt%): 32Bi₂O₃–68GeO₂, 42Bi₂O₃–58GeO₂, 47Bi₂O₃–53GeO₂, 52Bi₂O–48GeO₂, 62Bi₂O₃–38GeO₂. BGO glasses were prepared by traditional melt quenching method. To obtain the band gap values of fabricated BGO glasses, optical absorption spectra were used for evaluation of optical properties. The mass attenuation coefficients (μ/ρ) were achieved for prepared glasses at 0.015–15 MeV photon energies employing MCNPX Monte Carlo code and WinXcom program. Moreover, broad-range of nuclear shielding parameters for gamma ray, neutrons and charged particles such as mass attenuation coefficient, half value layer, effective atomic number, buildup factors, mass stopping powers, projected ranges, fast neutron removal cross sections and damage factors were calculated. The refractive index is calculated from E_opt, As Bi₂O₃ concentration is enhanced, E_opt is also increased as well as the optical electronegativity and consequently the refractive index. In addition, the results showed that BIGE5 glass sample with highest Bi₂O₃ contribution has excellent nuclear radiation shielding ability among the other fabricated glass samples.     

Phosphate glasses with improved optical properties

A study was undertaken to see how some components can affect the physicochemical properties of PbO−BaO−Al₂O₃−P₂O₅ optical glasses. The possibility is demonstrated for the manufacture of phosphate-base flint glasses with a high refractive index and improved transmission in the visible and UV regions of the spectrum. Translated from Steklo i Keramika, No. 2, pp. 3–5, February, 1997.     

计算机辅助玻璃组分设计

根据硅酸盐玻璃成分与物理性质的线性关系,利用VisualC 语言进行编程,实现玻璃组成成分的计算过程。通过对钨组、钼组以及铂组等多种电真空玻璃系统的性能计算与实际性能的比较分析可以看出,玻璃的密度、膨胀系数等性能参数的计算值和实测值具有非常好的一致性。采用VisualC 程序辅助玻璃成分设计,能够提高新型玻璃的研究效率。     

Optimization of compositions and properties of silver-free photochromic glasses

It is shown that optimization of the compositions and properties of photochromic glasses by standard parameters does not always give an optimum result because it is often necessary to use nonstandard reference parameters in addition to the standard ones in order to take into account all of the standard properties.Translated from Steklo i Keramika, No. 7, pp. 6 – 9, July, 1996,     

Optimization of the matrix compositions and properties of silver-free photochromic glasses

The matrix compositions of silver-free photochromic glasses were optimized by the simplex-lattice design method. The general region of photochromism in such glasses and the optimal region of matrix compositions were determined.     

Crystallizability of optical glasses and their melts

The crystallization parameters of some glasses from the native catalog which exhibit high crystallizability by the polytherrnal method from glass and from melt are compared. Crystallization characteristics obtained by the DTA method are considered. Practical recommendations are given.Translated from Steklo i Keramika, No. 4, pp. 8–10, April, 1995.     

Enhancement of the radiation resistance of cerium-containing fluorophosphate glasses through codoping with Sb2O3 and Bi2O3

The growing demand for radiation-resistant optical glasses for space and nuclear radiation applications has attracted significant research interest. However, radiation-resistant fluorophosphate glasses have been poorly studied. In this work, we report on the tailoring and performance of radiation-resistant fluorophosphate glasses that contained cerium through codoping with Sb₂O₃ and Bi₂O₃. The physical properties, optical properties, microstructure, and defects of fluorophosphate glasses were investigated using transmittance measurements, absorption measurements, as well as Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) spectroscopy. The results showed that the radiation resistance of all codoped fluorophosphate glasses was better than the undoped cerium-containing fluorophosphate glasses after 10–250 krad(Si) irradiation. Especially in glasses doped with Bi₂O₃, the optical density increment at 385 nm was only 0.1482 after 250 krad(Si) irradiation. The CeO₂ prevented the development of phosphate-related oxygen hole center (POHC) defects, whereas further codoping with Bi₂O₃ suppressed the formation of oxygen hole center (OHC) and POEC defects, reducing the breaking of phosphate chains caused by CeO₂. Bi³⁺ is more likely than Sb³⁺ to change the valence, affecting the transition equilibrium of intrinsic defects and reducing the concentration of defects produced by irradiation. When codoping with Sb₂O₃ and Bi₂O₃, Bi₂O₃ does not enhance radiation resistance owing to the scission effect of Sb₂O₃ on the phosphate chain, which is not conducive to the radiation resistance of glasses. This indicates that the cerium-containing fluorophosphate glasses doped with Bi₂O₃ can effectively suppress the defects caused by irradiation and improve the radiation resistance of the glasses.     

Effects of fluorinated substituents on the refractive index and optical radiation resistance of methacrylates

Novel fluorinated methacrylate polymers were synthesized. The purpose was to produce polymers with low refractive indices and increased resistance to optical radiation damage. Six different fluorinated substituents were appended on the monomer before polymerization. Optical-quality samples were prepared, and their transmission spectra, through 0.8 cm thick samples, were obtained. Each sample was tested for refractive index and glass transition temperature. The samples absorbed 10 MRad gamma radiation from a ⁶⁰Co source in an air environment; their transmission spectra were recorded immediately after irradiation and again after seven days had elapsed. As expected, increasing the fluorine content in the side chains resulted in decreased refractive indices. Fluorine content also influenced optical radiation stability. One polymer, poly(1H,1H-heptafluorobutyl methacrylate) retained superior UV/visible transmission after irradiation. © 1993 John Wiley & Sons, Inc.     

Mechanical and radiation shielding properties of tellurite glasses doped with ZnO and NiO

This study examines the basic mechanical parameters and radiation shielding properties of (100−x)TeO₂+xZnO+4NiO glasses (where x = 9.6, 19.2, 28.8, and 38.4 mol%) glass system. The mechanical study included basic parameters such as hardness, packing density, elastic moduli, and Poisson's ratio. Shielding ability of the glasses was tested against gamma and neutron radiations as well as against charged particles such as electron, proton, and alpha. Geant4 simulations and theoretical calculations by using Phy-X computer program were carried out to estimate mass attenuation coefficient (μ/ρ), neutron removal cross section (RCS), transmission factors namely; half value layer (HVL) and mean free path (MFP), and effective atomic number for total interaction of gamma (Z_eff-G), electron (Z_eff-E), proton (Z_eff-P), and alpha (Z_eff-A) radiations. The results showed that ZnO concentration had a significant influence on the mechanical properties and the shielding capability for glasses involved. The values effective atomic number were in the range of 30.2–46.1 for Z_eff-G, 21.2–26.5 for Z_eff-E, 16.9–19.7 for Z_eff-P, and 15.3–18.6 for Z_eff-A, respectively. The current glasses can act as superior shielding material as compared with those of Pb-free glasses, commercial glasses, and traditional concrete.     

Effect of radiation bleaching in sodium-silicate glasses

Radiation defects in the lattice of sodium-silicate glass that arise under the effect of γ-radiation were investigated by optical spectroscopy. Color centers of the hole type appeared in the glass at radiation doses in the 10²–10³ Gy region.     

Study of the iron-containing sodium borosilicate two-phase glasses and porous glasses by optical spectroscopy

The results of studying the iron oxide-containing two-phase sodium borosilicate glass and porous glass based on it using the method of optical spectroscopy in the visible and infrared regions are presented. Decoding the transmittance spectra of this glass in these spectral ranges using the literary data and their comparative analysis with two-phase sodium borosilicate glass that does not contain iron were carried out.     

Fluorophosphate glasses doped with PbSe quantum dots and their nonlinear optical characteristics

A new fluorophosphate glass matrix containing PbSe quantum dots characterized by a narrow size distribution (ΔR/R ∼ 5–7%, where R is the size of a quantum dot) is prepared under heat treatment. It is demonstrated that fluorophosphate glasses can be doped by introducing (ZnSe + PbO) or PbSe into the composition of the glass. The optical absorption spectra of the quantum dots corresponding to the strong quantum confinement regime are studied over a wide range of quantum-dot sizes (4–18 nm). The nonlinear optical absorption is investigated at a wavelength of 1.54 μm. It is revealed that the introduction of (ZnSe + PbO) rather than of PbSe into the composition of the glass improves the bleaching contrast owing to a more uniform distribution of the quantum dots over the volume of the glass sample.