Intense green luminescence in Mn-doped gallogermanate nanostructured glass

Mn activated optical materials have been demonstrated to be promising for various applications such as light-emitting device, tunable lasers and smart sensors. Most of the candidates belong to the single crystals and crystalline powders and few reports involve about the glass-derived materials. In this letter, we report the fabrication of active Mn-doped nanostructured glass sample via control of the crystallization of a typical gallogermanate glass. LiGa5O8 and LiGaGeO4 can precipitate after heat-treatment and Mn centers selectively incorporate into the crystalline phase. Importantly, the luminescence can be switched from red to green color and the intensity can be simultaneously enhanced. Furthermore, the luminescence properties can be tuned via control of the phase of the nanostructured glass. The approach should be general to various transition metal dopant, thus may potentially pave an effective way for functionalization of glass and expand the category of the active optical materials.

Enhancement of Gamma-ray Shielding Properties in Cobalt-Doped Heavy Metal Borate Glasses: The Role of Lanthanum Oxide Reinforcement

The direct influence of La3+ ions on the gamma-ray shielding properties of cobalt-doped heavy metal borate glasses with the chemical formula 0.3CoO-(80-x)B2O3-19.7PbO-xLa2O3: x = 0, 0.5, 1, 1.5, and 2 mol% was examined herein. Several significant radiation shielding parameters were evaluated. The glass density was increased from 3.11 to 3.36 g/cm3 with increasing La3+ ion content from 0 to 2 mol%. The S5 glass sample, which contained the highest concentration of La3+ ions (2 mol%), had the maximum linear (μ) and mass (μm) attenuation coefficients for all photon energies entering, while the S1 glass sample free of La3+ ions possessed the minimum values of μ and μm. Both the half value layer (T1/2) and tenth value layer (TVL) of all investigated glasses showed a similar trend of (T1/2, TVL)S1 > (T1/2, TVL)S2 > (T1/2, TVL)S3 > (T1/2, TVL)S4 > (T1/2, TVL)S5. Our results revealed that the S5 sample had the highest effective atomic number (Zeff) values over the whole range of gamma-ray energy. S5 had the lowest exposure (EBF) and energy absorption (EABF) build-up factor values across the whole photon energy and penetration depth range. Our findings give a strong indication of the S5 sample’s superior gamma-ray shielding characteristics due to the highest contribution of lanthanum oxide.

Investigation of Light Parameters on Image Quality and Optical Coherence Tomography

In this work, image quality and optical coherence tomography were studied. The results of the study show that there is a very significant difference between ultrasound and optical coherence tomography to produce an image with a different wave. To understand this, we studied the basic principle of optical coherence tomography in the Michelson interferometer using monochromatic and broadband sources. Time-domain and spectral-domain measurements, which exist at the detector level, are briefly described using a glass sample. The time-domain signal strength of the Michelson interferometer using a broadband source is a Gaussian envelope.

Investigation of Er3+ Ions Reinforced Zinc-Phosphate Glasses for Ionizing Radiation Shielding Applications

Melt quenching technique is used for preparing glasses with chemical formula (70P2O5)−(16−x)CdO−(14ZnO)−(xEr2O3), (x = 1–6 mol%) . These glasses were named Er1, Er2, Er3, Er4, Er5, and Er6, respectively. Photon buildup factors, fast neutron absorption, and electron stopping of the prepared glasses were examined. Glasses’ density was varied from 3.390 ± 0.003 for the Er1 glass sample to 3.412 ± 0.003 for the Er6 glass sample. The Buildup factor (BUF) spectra have relatively higher values in the Compton Scattering (CS) dominated areas compared to both Photoelectric effect (PE), and Pair Production (PP) dominated energy regions. The highest BUF appeared at the Er atom K-absorption edge, whose intensity increases as the molar concentration of Er2O3 in the glasses increases. The photon absorption efficiency (PAE) of the glasses increases according to the trend (PAE)Er1 < (PAE)Er2 < (PAE)Er3 < (PAE)Er4 < (PAE)Er5 < (PAE)Er6. Fast neutron removal cross-section, FNRC values of the glasses obtained via calculation varied from 0.1045–0.1039 cm−1 for Er1–Er6. Furthermore, the continuous slowing down approximation mode (CSDA) range enhances the kinetic energy of electrons for all glasses. Generally, results revealed that the investigated glasses could be applied for radiation shielding and dosimetric media.

Crystallization and Dielectric Properties of BaO-SrO-PbO-TiO2-Nb2O5-SiO2 Glass-Ceramic Composites with La2O3 Addition

Glass-ceramic composite samples with different La2O3 content were prepared via melt-quenching followed by controlled crystallization. X-ray diffraction(XRD) analysis reveals that when the addition amount of La2O3 in the glass sample is less than 1mol%, two phases of perovskite structure and tungsten-bronze structure are formed after annealing at 1000°C for 3h. When the addition amount of La2O3 in the glass sample is increased to 2mol%, a new phase of pyrochlore structure is formed. Moreover, the addition of La2O3 causes the change in the lattice parameters of the glass-ceramic crystal phase. The microstructure observed that the ceramic phase grain size is in the nanometer level. The shape of some grains becomes an elongated structure when the La2O3 content in the sample increases to 2 mol%, and the grain size is increased significantly. The dielectric constant of the BaO-SrO-PbO-TiO2-Nb2O5-SiO2 glass-ceramic system is decreased with the increase of La2O3 addition, and the dielectric loss of the sample is decreased to the range of 0.003-0.008. The electric field stability of the dielectric constant was significantly improved with the addition of La2O3, indicating that adding a certain proportion of La2O3 to the BaO-SrO-PbO-TiO2-Nb2O5-SiO2 glass-ceramic system can effectively improve the dielectric properties, and it has a promising application as a dielectric material.

Newly Developed Vanadium-Based Glasses and Their Potential for Nuclear Radiation Shielding Aims: A Monte Carlo Study on Gamma Ray Attenuation Parameters

This study aimed to investigate different types of glasses based on the 46V2O5-46P2O5-(8-x) B2O3-xCuO system in terms of their nuclear radiation shielding properties. Accordingly, five different CuO-doped vanadate glasses were investigated extensively to determine the necessary gamma shielding parameters along with effective conductivity at 300,000 and buildup factors. Phy-x PSD software was used for determination of these vital parameters. Furthermore, these parameters, such as half value layer, tenth value layer, and mean free path were investigated in a broad energy range between 0.015 and 15 MeV. The results revealed that the amount of CuO reinforced in each sample plays an essential role in determination of the shielding abilities of the samples. The sample with the highest CuO content had the highest linear attenuation coefficient and mass attenuation coefficient values. Additionally, the lowest mean free path, half value layer, and tenth value layer values were recorded for glass sample VPCu8. There was an inverse relation between the effective conductivity and effective atomic number and photon energy; that is, as energy increases, the effective conductivity and effective atomic number decreased rapidly, especially in the regions of low energy. Glass sample VPCu8 reported the highest values for both parameters. Moreover, glass sample VPCu8 had the lowest exposure buildup factor and energy absorption buildup factor values. Our findings showed that CuO-reinforced vanadate glass composition, namely 46V2O5-46P2O5-8CuO, with a glass density of 2.9235 g/cm3, was reported to have superior gamma ray attenuation properties. These results would be helpful for scientists in determining the most appropriate additive rare earth type, as well as the most appropriate glass composition, to offer shielding characteristics similar to those described above, taking into consideration the criteria for usage and the needs of the community. The results of this research will be useful to the scientific community in evaluating the prospective characteristics of CuO-doped glass systems and related glass compositions. CuO-doped glass systems and associated glass compositions have a wide range of properties.

An Evaluation of the Shielding Effectiveness of Tellurite Glass with Composition 85TeO2-5Nb2O5-5ZnO-5Ag2O for Diagnostic Radiology Application

The metal oxide glasses have attracted huge interest as promising types of shielding materials to replace the toxic, heavy and costly conventional shielding materials. In this work, the physical and the shielding effectiveness of Tellurite glass sample (S1) contain host metal oxides (85TeO2-5Nb2O5-5ZnO-5Ag2O) were evaluatedatphoton energies range between 15keVand1MeV.The shielding parameters of the proposed glass system such as linear attenuation coefficients, HVL, MFP, Zeff, and Neffwere evaluated. The proposed samples showed a superior performance at the diagnostic energy range between 40 and 90 keV and a comparable shielding effectiveness above 90keV when compared with other commercial standard shielding materials.

Synthesis of Pb3O4-SiO2-ZnO-WO3 glasses and their fundamental properties for gamma shielding applications

In this research, we prepared zinc lead silicate glass system with the composition 35Pb3O4-60SiO2- (5-x) ZnO-xWO3 (0 ≤ x ≤ 5 mol %) via the melt-quench method. XRD is explored the nature of the glass system. Ultrasonic velocity, and elastic modulus were experimentally investigated and then the results were confirmed by using the theoretical calculations. It was found that because of molar volume reduction inter-ionic distance\({R}_{i}\), polaron radius \({r}_{p}\), and inter-nuclear distance, \({r}_{i}\)of the investigated glasses are reduced with WO3 content. The basic attenuation factors; mass and linear coefficients denoted by µ/ρ and µ, respectively, were determined employing several simulations for each energy via FLUKA code. As WO3 content increased from 0 to 5 mol %, the µ increased from 0.728 cm− 1 to 0.856 cm− 1 achieving high shielding performance for the sample with x = 5 mol %. At 0.6 MeV with x = 5 mol %, we found that the dose rate of the prepared glass system decreases from 2.35 × 107 R/h at 1 mm to 4.71 × 106 R/h at 4 mm. The values of MFP and HVL are lower than those of the conventional photon shields indicating that our prepared glass samples (especially G5 glass sample) have promising shielding properties to use for x/gamma rays applications.

Up-Conversion Luminescence Properties of Nd3+/Yb3+ Doped Lutetium-Based Oxyfluoride Glass Ceramic

Nd[Formula: see text]/Yb[Formula: see text] co-doped lutetium-based glass sample and glass ceramic sample were prepared with the molar ratios of 52SiO2-8Na2CO3-16Al2O3-33NaF-3LuF3-0.15Yb2O3-0.03Nd2O3 by the high temperature melting method in 1400∘C. Under the excitation of 980[Formula: see text]nm diode laser, up-conversion luminescence spectrum of glass sample and glass ceramic sample was measured and three stronger up-conversion luminescence peaks at the wavelength of 552[Formula: see text]nm, 656[Formula: see text]nm and 668[Formula: see text]nm were observed, and up-conversion luminescence strengths of glass ceramic sample are higher than those of glass sample. The two-photon absorption of three emission peaks was determined by the fitting curve graph of up-conversion emission power and LD wording current. Absorption spectrum of glass ceramic sample was obtained and spectral strength parameters were computed as [Formula: see text][Formula: see text]cm2, [Formula: see text][Formula: see text]cm2, [Formula: see text][Formula: see text]cm2 by adopting Judd–Ofelt theory, and the root mean square deviation between the theoretical oscillator strength and the experimental oscillator strength were calculated as [Formula: see text]. Transition probability, branching ratio of 4F[Formula: see text] to its lower level and lifetime of 4F[Formula: see text] level of Nd[Formula: see text] ions were calculated, and the results indicate that the prepared Nd[Formula: see text]/Yb[Formula: see text] co-doped glass ceramic sample is a kind of good up-conversion material.