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In the world of contemporary glass research, the subtle interplay between composition and resulting properties is of paramount importance. The structural, optical, and gamma-ray attenuation properties of BiNb(x) glasses having a formula x Bi 2 O 3 –(20- x)Nb 2 O 5 –B 2 O 3 –Li 2 O–SiO 2 (where x = 0,5,10,15 and 20 mol%) were investigated. This study delves deep into the transformative role of Bi 2 O 3 when introduced into the glass matrix, a journey from opacity to enlightening transparency. The density of the BiNb glass system was found to increase from 4.579 g/cm3 for pristine to 5.439 gm/cm3 for BiNb20. XRD analysis testifies the transfer of a pristine sample from a crystalline to a fully amorphous, with Bi 2 O 3 as the catalyst. UV–visible spectra were investigated, and optical parameters were extracted. The optical bandgap (E g) was decreased from 4eV for BiNb0 to 3.83eV for BiNb20. In addition, E g value was used to evaluate the refractive index of the prepared BiNb glasses using various theoretical models. The refractive index of the Moss model increases from 2.208 for BiNb0 to 2.229 for BiNb20, besides the Moss, Herve-Vandamme, and Kumar-Singh models are compatible. The studied glass samples show a metallization criterion within the range of 0.434–0.447, indicating the potential for new optical materials with good nonlinearity. Moreover, gamma rays with energy ranging from 0.015 MeV to 15 MeV are used to highlight the shielding capabilities of the glasses. As the Bi 2 O 3 fraction increases and the Nb 2 O 5 decreases, the shielding capability of the prepared BiNb glass system increases. • The glass system with the formula x Bi 2 O 3 –(20- x)Nb 2 O 5 –B 2 O 3 –Li 2 O–SiO 2 (where x = 0,5,10,15 and 20 mol%) was synthesized. • The impact of replacing Nb 2 O 5 with Bi 2 O 3 on structural, optical , and gamma-ray attenuation properties was investigated. • The optical parameters including bandgap and refractive index of the glass system were investigated. • The mass attenuation coefficient of samples was evaluated using Phy-X_PSD at photon energies ranging from 0.015 to 15 MeV. [ABSTRACT FROM AUTHOR]

Coatings that transmit visible light and shield near-infrared (NIR) rays of sunlight have potential applications in smart windows, thermal camouflage, and heat shielding encapsulations. Here, we report metal oxide-dispersed polymer nanocomposites as potential coating materials that possess a combination of NIR reflection and visible light transmission. Film coatings (∼600 μm) comprising nanocrystalline zinc oxide (ZnO), titanium dioxide (TiO 2), and cupric oxide (CuO) in the range of 0–2 wt% in polydimethylsiloxane (PDMS) matrix are fabricated. At optimal compositions, these coatings provided up to 52 % reduction in the interior air temperature, measured at distances ∼3 cm beneath the surface, while, at the same time, retaining up to 70 % of visible light transparency. The NIR reflection may be attributed to a combination of the band gap of the pigment material and the difference between the refractive indices of the pigments and the polymer matrix. We present a design map that highlights different regimes of heat-shielding and light transmission space for PDMS nanocomposite films. The performance, when compared with existing reports, suggests that films fabricated in this work outperform previously reported polymeric coatings in providing a combination of heat shielding and optical transparency. [Display omitted] • ZnO, TiO 2, and CuO-dispersed PDMS films are fabricated by doctor blade coating. • Films with 0.45 wt% metal oxides in PDMS exhibit 74–80 % visible light transmittance. • Films with 0.45 wt% ZnO/TiO 2 -dispersed PDMS have the best heat shielding performance coefficient of ∼0.5. • Design map showing the trade-off between optical transparency and NIR reflectivity is developed. • Refractive index and band gap of pigment material are identified as major factors determining NIR reflection. [ABSTRACT FROM AUTHOR]

This article is devoted to studying the optical properties of a novel single-crystal LiTi 2 O 4 thin film. A high-quality (011)-oriented LiTi 2 O 4 single-crystal thin film was prepared on a MgAl 2 O 4 (011) substrate by pulsed laser deposition. The weak in-plane optical anisotropy is discovered by Mueller-matrix spectroscopic ellipsometry, which can be attributed to the cooperative Jahn-Teller distortion in the Ti–O octahedrons. The pseudo-dielectric functions were determined in the photon energy of 1.24–5.06 eV using the ellipsometric spectra. The optical conductivity, plasma frequency, effective mass, scattering time and other dielectric-related factors are also discussed. The critical points obtained in the pseudo-dielectric functions are originated from the charge-transfer transitions of the Ti related pairs. The results demonstrate that the enhanced effective mass is responsible for the high optical transparency of LiTi 2 O 4 rather than the large high frequency dielectric constant ε ∞. • The weak in-plane optical anisotropy was first observed by MMSE. • The optical transitions in LTO are originated from charge transfer transitions of Ti related pairs or isolated Ti ions. • The optical transparency of LTO is dominantly originated from the enhanced effective mass rather than large ε ∞ . [ABSTRACT FROM AUTHOR]

8YSZ precursor was synthesized by the co-precipitation method using ammonia as the precipitant. The influences of calcination temperature on the phase, morphology and dispersity of 8YSZ nanopowders were investigated. It was found that the 8YSZ nanopowders calcined at 800 °C had the best sinterability with the mean particle size of 14.5 nm. 8YSZ ceramics were then fabricated by air pre-sintering at 1250–1325 °C followed by HIP post-treatment at 1550 °C. The influences of pre-sintering temperature on the microstructure and optical transparency of 8YSZ ceramics were studied. It was found that the 8YSZ ceramics pre-sintered at 1300 °C had a suitable microstructure. The HIP post-treatment temperature was successfully reduced by 200 °C for the 8YSZ transparent ceramics from co-precipitated powders compare with our previous works. In-line transmittance of the 8YSZ ceramics (1.0 mm in thickness) reached 65.7% at 800 nm and the average grain size was 25 μm. • The 8YSZ nanopowders calcined at 800 °C showed the best dispersity and highest sinterability. • The 8YSZ ceramics pre-sintered at 1300 °C had a uniform microstructure with the small diameter ratio of pore/grain. • The HIP temperature was successfully reduced by 200 °C for 8YSZ transparent ceramics from co-precipitated powders. • In-line transmittance of the 8YSZ ceramics is 65.7% at 800 nm and the average grain size is 25 μm. [ABSTRACT FROM AUTHOR]

Optical properties and morphology of polymer films based on diglycidyl ether of bis-phenol A and on natural compound 3,5,7,3′,4′–pentahydroxyflavone (quercetin) using UV–vis spectroscopy, scanning electron microscopy and powder X-ray diffraction methods have been investigated. The influence of ordering degree of the polymers, flexibility of their chains, intensity of intermolecular interaction between the quercetine moieties on the polymers' morphology was discussed. It is shown that all the quercetine-based polymer films are transparent at visible and near infrared regions beginning from 420 to 450 nm. Low optical transparency in the short-wavelength region can be explained the self-absorption of quercetin moieties in the polymer chains. [ABSTRACT FROM AUTHOR]

Broadband metamaterial absorber (MMA) with optically transparent property is essential for solving the electromagnetic pollution problem at gigahertz. In this work, we designed and prepared a sandwich MMA consisting of high-transmittance substrate polymethyl methacrylate (PMMA), a periodically arranged indium tin oxide (ITO) film, and a low resistivity ITO reflective layer. The microwave absorbance over 90% can be achieved in the frequency range of 6–17.8 GHz. Wide-angular stability, good polarization insensitivity and optical transmittance to visible light (400–800 nm) are realized. The microwave attenuation mechanisms of the proposed MMA were investigated by surface current distribution and power loss density. The excellent microwave absorption and optical transmittance properties indicate the strong potential and feasibility of the designed MMA for the development of optically transparent microwave absorbing windows and devices. • Broadband microwave metamaterial absorber with optical transparency was designed. • The microwave absorbance over 90% can be achieved within 6–17.8 GHz. • The metamaterial absorber has polarization insensitive and wide-angle stability properties. [ABSTRACT FROM AUTHOR]

(2-Azoniaethyl)guanidinium dichloride ( AEGCl ), a salt of a functional guanidine derivative, was prepared and characterised by single-crystal and powder X-ray diffraction analysis, elemental analysis and by NMR, UV–Vis and vibrational spectroscopy. The crystal structure of AEGCl , which crystallises with the symmetry of the chiral space group P 2 1 , is built up via simple and multicentred N H⋯Cl hydrogen bonds and further supported by C H⋯Cl contacts. The compound is thermally robust and exhibits promising NLO properties with powder SHG efficiency better than potassium dihydrogen phosphate. In contrast, (2-azoniaethyl)guanidinium salts with inorganic oxoanions such as (2-azoniaethyl)guanidinium dinitrate and diperchlorate, synthesised for a comparison, form centrosymmetric crystal assemblies having several structurally independent “molecules” in their structures. [ABSTRACT FROM AUTHOR]