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The first principles calculation is implemented to predict the phase stability, optical activities and magneto-electronic characteristics of cubic MAlO3 (M = Ce, Pr) perovskites. The optimized structural parameters authenticate the stability of the ferromagnetic state, and also it is confirmed by enthalpy of formation (ΔHf). Stability of MAlO3 compounds is verified with the help of tolerance factor ( τ ) in the cubic phase. The density of states (DOS) and spin polarized band structure (BS) elucidate the ferromagnetic half metallic (HM) type of MAlO3 compounds, with Ce/Pr-f states play a major role. The calculated value of magnetic moment increases from cubic CeAlO3 (1 μB) to PrAlO3 (2 μB), and Ce and Pr atoms enormously contribute in magnetization. Moreover, various optical parameters such adsorption coefficient, dielectric constants, reflectivity, optical conductivity and refractive indexare also studied. The outcomes recommend that these perovskites might be suitable candidates for optical and spintronic devices.

The present study investigates the transient spectrum (TS) of a two-level system that interacts with a generalized squeezed state without using the rotating wave approximation (RWA). We consider the purity of the optical field, which is developed in a generalized squeezed state, utilizing the linear entropy. The analytic expressions of the TS and field purity (FP) of the bipartite system are evaluated. Moreover, the study exhibits the influence of the squeezed parameter and some photons transition on the TS and FP. We obtain that the control of the FP may be generated based on an adequate choice of the photons transition and squeezed parameter. Such results can be utilized in the understanding and development of various tasks of quantum physics and optics.

This paper reports the tailored visible light emission (blue, green and white) traits of the colloidal silicon quantum dots (SiQDs) integrated with zinc (ZnSiQDs). These QDs were derived from the PSi etched with Zn powder. The ZnSiQDs was prepared via the photo-electrochemical etching process (40 mA/cm2 for 20 min) of the n-type Si wafer immersed inside the solution made from the hydrofluoric (HF) acid to ethanol (ET) volume ratios of 7:1 and 7:3 with the Zn powder (0.17 g) inclusion. The as-prepared samples (named as ZnSiQDs-7:1 and ZnSiQDs-7:3) were characterized to determine the influence of HF:ET on their structure, morphology and optical characteristics. The XPS analyses of the samples revealed the formation of ZnO. The FESEM images exhibited the growth of PSi layer of thickness 8.192 μm and 7.073 μm for the ZnSiQDs-7:3 and ZnSiQDs-7:1 samples, respectively. The EFTEM image analyses showed the nucleation of the ZnSiQDs of average diameter 2.7 nm (for ZnSiQDs-7:3) and 1.33 nm (for ZnSiQDs-7:1). The band gap energy for both samples estimated from the absorption spectra was 3.6 eV. The emission spectra of the studied ZnSiQDs under three different excitation wavelengths disclosed the intense visible peaks (blue, green and white) in the range of 385–700 nm. This observation was mainly ascribed to the effects of quantum confinement and ZnO surface layer on the SiQDs that minimized the silicon oxidation. It is established that by controlling the HF to ET volume ratio the visible luminescence of the ZnSiQDs can be customized, useful for diverse optoelectronic applications.

A new glass system with a chemical formula (60-x) B2O3+20Bi2O3 +20Li2O+ xSm2O3: x = 0, 1.25, 2.5, 3.75 and 5 wt% was synthesized using the solid-state conventional approach. The density of the newly fabricated glasses was determined using the Archimedes method. The glasses’ structure was studied utilizing the X-ray diffraction spectroscopy. Moreover, some of the most effective optical features such as the refractive index (n), energy gap (Eg), and Urbach energy (Eu) were determined based on the absorbance obtained from the UV-visible spectrum. Furthermore, the radiation shielding capacity of the newly fabricated samples was assessed utilizing the Monte Carlo Modeling (MCNP 5) code and Phy-X/PSD software. The calculated mass attenuation coefficient (MAC) values at 0.015 MeV were observed to increase from 21.893 to 25.570 cm2 g−1 for glasses BBLS1 and BBLS5 respectively. Simulations demonstrated that the MAC of the fabricated glasses enhanced with the insertion of the Sm2O3 contents. Besides, the buildup factors (EBF and EABD) were calculated using the program Phy-X/PSD. The removal cross-section ƩR for the fast neutrons was theoretically calculated. The calculated results showed the ƩR varied in the range between 0.170 and 0.241 cm-1 for glasses BBLS1 and BBLS5 respectively. The recorded results depict that the insertion of Sm2O3 enhances the optical, gamma-ray, and neutron shielding capacities.

The broadband visible photoluminescence (PL) from photoelectrochemical etched porous silicon quantum dots (PSi-QDs) containing zinc (Zn) powder is reported. The influence of the Zn content (0, 0.11, 0.17, and 0.25 g) on the structure, morphology, and room-temperature PL characteristics of the PSi-QDs were evaluated. The PSi-QDs were prepared in HF:ethanol solution by electrochemical etching of n-type Si at the optimum etching time and current density with varying masses of added Zn powder. The PL spectra of the as-prepared samples exhibited a broad emission peak in the region of 510–760 nm with the highest intensity at approximately 657 nm. The inclusion of Zn powder in the PSi-QDs was observed to enhance the PL peak intensity by a factor of seven. The improved visible light emitting traits were attributed to the quantum confinement (QC) effect, which widened the energy band gap (1.12–2.5 eV) of the Zn-included PSi-QDs. The present findings may contribute to the development of PSi-QD-based red phosphors and other optoelectronic applications. EDX and FESEM analysis showed that porous silicon etched with Zn mass is mainly composed of oxygen, fluoride, zinc, and silicon.

A novel glass system consists of six glasses was fabricated using melt quenching process according the chemical formula (60-x) B2O3+20Na2O2+20Bi2O3 +xWO3: x = 0, 1, 2, 3, 4 and 5 wt%. Archimedes method was used to determine the density and molar volume of the fabricated glasses. Moreover, the X-ray diffraction technique was used to show the variation of the amorphous phase with the addition of WO3 contents for the fabricated glasses. The optical features such as the refractive index (n), energy gap (Eg), distribution energy (Ed) and oscillation energy (Eo) were calculated based on the absorbance obtained from the UV-visible spectrum. The electromagnetic radiation (gamma ray) shielding capacity was evaluated using Monte Carlo simulation (MCNP 5) code in addition to Phy-X program. The results showed that the highest linear attenuation coefficient (LAC) occurred at 0.015 MeV and increased from 99.532 to 138.656 cm−1 for glasses coded as W 1 and W 6 respectively. The obtained results showed an enhancement of gamma ray shielding capacity with the addition of WO3 (wt%) to the fabricated glasses. Based on the estimated LAC, other shielding properties were calculated such as the glass half value layer (HVL), mean free path (MFP) and effective atomic number (Zeff). Finally, the ability of the fabricated glasses to resist the charged particles (alpha and proton) and uncharged neutrons were also estimated using SRIM program and theoretical calculation. The obtained results refer that the insertion of WO3 contents improves the shielding capacity for alpha and protons while it reduces the effective removal cross section of the fabricated glasses.

A series of six tungsten-based bismuth borate glasses with a xWO3- 20 Bi2O3- 20 Na2O2- (60-x) B2O3), 0≤ x ≤ 5 wt% chemical composition were synthesized by using the solid-state conventional method. The structures of the fabricated samples were studied with X-ray diffraction analysis. Optical features such as the energy gap (Eg), Urbach energy (Eu), steepness parameter (S), refractive index (n) and Fermi level energy (EF) were measured for the fabricated glasses with a UV–Vis–NIR spectrophotometer. Furthermore, a Monte Carlo simulation code (MCNP-5) was applied to estimate the gamma ray mass attenuation coefficient (MAC) for the fabricated glasses. The simulated data showed that the insertion of WO3 increases the MACs of the fabricated samples: the highest and lowest MACs were obtained for the W6 and W1 glasses, respectively. Then, the simulated MAC was used to calculate the mean free path (MFP) for all the fabricated glasses. The thinnest MFP was achieved by W6 (increasing from 0.007 to 70,560 between 0.015 and 15 MeV, respectively), while the thickest MFP was achieved by W1 (increasing from 0.0100 to 8.975 between 0.015 and 15 MeV, respectively). Moreover, new Phy-x/PD software was used to calculate MAC, MFP, equivalent atomic number (Zeq) and the exposure and energy absorption buildup factors (EBF and EABF). The simulated and calculated results showed that adding WO3 enhances the shielding properties of the synthesized glass.