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In the present study, for the first time the machine learning (ML) based refractive index (n) approach is established depends on the density (ρ) parameter of glasses for a dataset of 2000 oxide glasses to predict refractive index of B2O3-CaO-Li2O-Sb2O3 glasses. Density of the investigated glasses varied from 2.56 to 2.97 gm/cm3. The corresponding refractive index was changed from 2.540 to 2.405. The refractive index prediction based on density parameter derived from the density of glasses and constant 'K'. For all M-L techniques including gradient descent (GD), artificial neural network (ANN), and random forest regression (RFR), the density factor is used as an independent variable and the experimental refractive index as a dependent variable. The data set of 10,000 oxide glass samples was employed to forecast density using a variety of machine learning approaches. In comparison to other models, the Random forest regression (RFR) model fitted the glass data with the highest R2 value of 0.949 for refractive index prediction and 0.925 for density prediction. For both the prediction of density and refractive index, the R2 is controlled to 0.932 and 0.9223, respectively. The highest R2 values for refractive index and density prediction were gained when the tanh activation function was used in an artificial neural network (ANN) with varied activation functions. [ABSTRACT FROM AUTHOR]

In this study, the role of TiO2 on the physica, and optical properties as well as the γ-ray protection features of a set of six glass samples with the chemical formula (65-X)B2O3–15BaO–5Bi2O3–15ZnO–XTiO2, where X = 0–10 mol% in the step of 2% have been investigated. The density (ρ) increased gradually from 3.70 to 3.93 g/cm3 and the molar volume (Vm) reduced from 27.71 to 26.72 cm3/mol as the TiO2 content increased from 0 to 10 mol%. By the inclusion of TiO2 in the glass networks, some absorption bands in the ultraviolet and visible regions are formed. Values of the indirect optical band gaps (Eg) were 2.550, 2.510, 2.470, 2.370, 2.270, and 2.180 eV for Ti-0.0, Ti-2.0, Ti-4.0, Ti-6.0, Ti-8.0, and Ti-10.0 glasses, respectively. The linear refractive index (n0) calculated values varied from 2.515 to 2.631. The linear-attenuation coefficient ( μ) followed the order: Ti-0.0 < Ti-2.0 < Ti-4.0 < Ti-6.0 < Ti-8.0 < Ti-10.0. The sample coded as Ti-10.0 glass sample (highest content of TiO2) has the lowest half (HVL) and tenth (TVL) value layer. Within the investigated energy range of within the range: 51.590–19.480, 50.676–19.722, 50.696–19.833, 50.271–20.012, 49.860–20.193, and 49.460–20.376 for the prepared samples Ti-0.0, Ti-2.0, Ti-4.0, Ti-6.0, Ti-8.0, and Ti-10.0 glasses, respectively. Results confirmed that the suggested titanium bismo-borate glasses can be used in the optical field and as alternative materials for radiation shielding applications. [ABSTRACT FROM AUTHOR]

In the present article, samples of erbium (Er)-doped bismo-borate glasses have been fabricated with general chemical compositions: 70B2O3–10CaO–10Li2O−(10-x)Bi2O3− xEr2O3: 0 (Er-0.0) ≤ x ≤ 1 (Er-1.0) mol% using the conventional melt-quench process. The impact of Er3+ ions on the structure and optical (linear and nonlinear) characteristics of Er-0.0/Er-1.0 glass blocks have been investigated. XRD measurements showed the lack in crystallinity of the prepared samples. In the range of UV-Vis measurements, there are absorption bands attributed to the electronic transitions (4f−4f) of Er3+ ions. The absorption bands seen at wavelengths of approximately 366, 379, 409, 452, 490, 523, 545, 653, 797, and 978 nm are associated with electronic transitions from the ground state, 4I15/2, to several excited states, namely 4G9/2, 2G11/2, 2H9/2, 4F5/2, 4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2, and 4I11/2, respectively. The optical band gap (Eg) values ranged from 2.61 to 3.11 eV for Er0.0 to Er1.0 glass samples, respectively. Values of linear refractive index (n0) ranged from 2.498 to 2.374. Values of the nonlinear refractive index varied from 7.76 to 4.99, while the third order non-linear optical susceptibility (χ(3)) values ranged from 5.14 to 3.14 for Er0.0 to Er1.0 glasses, respectively. Therefore, the suggested glasses can be used in several optical applications such as opto-electronic devices. [ABSTRACT FROM AUTHOR]

This study investigates the synthesis, physical, vibrational, optical, and dielectric characteristics of bismuth-borate barium glasses doped with chromium, with the aim of exploring their potential for use in optical applications. The chemical formula of the proposed glasses was (70-x)B2O3 − 10Bi2O3 − 20BaO − xCrO3: x = 0 (BBBCr0.0) − 0.5 (BBBCr0.5) mol%. The structure nature was examined. The physical features, FTIR spectroscopy, and linear/nonlinear optical properties have been investigated. Based on the XRD measurements, the prepared glasses were amorphous in nature. The density (ρ) of the glasses slightly decreased, while the molar volume (Vm) increased with increasing CrO3 content in the glass network. The percentage fraction of BO4 (N4) gradually increased at the expense of the percentage fraction of BO3 (N3) as the chromium content increased up to 0.2 mol%. However, for concentrations of chromium over 0.2 mol%, a reverse transformation from BO4 to BO3 was detected. The optical energy bands (Eg) changed from 3.07 to 1.41 eV, whereas the linear refractive index (n0) changed from 2.38 to 2.98 for BBBCr-glasses. The metallization criterion (M) values ranged from 0.392 to 0.265, indicating that the glasses have a wide range of potential for use in various optical applications. In addition, the nonlinear refractive index (n2) values ranged from 3.26 × 10−11 to 26.35 × 10−11 (esu), while the χ(3) values varied from 5.16 × 10−12 to 33.34 × 10−12 (esu) for the BBBCr-glasses with chromium concentrations ranging from 0.0 to 0.5 mol%. The real part of permittivity has the same value with chromium doping up to 0.2 mol% and then it is highly increased for concentrations greater than 0.2 mol%. The findings of this study highlight the potential of bismuth-borate barium glasses doped with chromium as a highly versatile and adaptable material for use in a range of optical applications. [ABSTRACT FROM AUTHOR]

In this work, (Ni 0.5 Pb 0.5 Fe 2 O 4) nano-ferrites has been prepared by a flash auto combustion technique, then new films of polyvinyl chloride (PVC) doped with x(Ni 0.5 Pb 0.5 Fe 2 O 4) nanoparticles: x = 0 (PVC/PNF0) – 10 (PVC/PNF10) wt% have been fabricated. The nature, physical, linear optical as well as γ-ray attenuation capacity of the fabricated PVC/(Ni 0.5 Pb 0.5 Fe 2 O 4) nanocomposites (NCs) sheets have been investigated. The crystalline state of (Ni 0.5 Pb 0.5 Fe 2 O 4) NPs, and amorphous state of pure PVC, and PVC/(Ni 0.5 Pb 0.5 Fe 2 O 4) films were performed by XRD measurements. The density (ρ) increased from 1.4451 to 2.613 g cm−3 for PVC/PNF0 and PVC/PNF10 sheets as the (Pb 0.5 Ni 0.5 Fe 2 O 4) NPs content increased from 0 to 10 wt%. The direct band gap (E g a p d i r e c t ) decreased from 5.259 to 2.969 eV, whereas Urbach energy (E U) increased from 0.439 to 4.812 eV. The index of refraction (n) for the fabricated films increased with increasing the concentration of (Ni 0.5 Pb 0.5 Fe 2 O 4) NPs. The highest and lowest mass attenuation coefficient (MAC) values possessed at 0.015 and 15 MeV, respectively. The effective atomic number (Z eff) of the currently films followed the trend: (Z eff) PVC/PNF0 < (Z eff) PVC/PNF1 < (Z eff) PVC/PNF3 < (Z eff) PVC/PNF5 < (Z eff) PVC/PNF10. The half value layer (HVL) parameter possessed the trend: (HVL) PVC/PNF0 > (HVL) PVC/PNF1 > (HVL) PVC/PNF3 > (HVL) PVC/PNF5 > (HVL) PVC/PNF10. The fabricated PVC/(Ni 0.5 Pb 0.5 Fe 2 O 4) NCs films can be used in electronic, optical, and radiation shielding applications. • PVC doped with Ni-Pb spinel nano-ferrites samples has been fabricated. • Physical properties of the investigated nanocomposites have been studied. • Linear optical properties have been investigated. • Capacity of radiation attenuation of the fabricated films has been evaluated. [ABSTRACT FROM AUTHOR]