Barium Borate Research Articles

A Polymorph of Dipeptide Halide Glycyl-L-Alanine Hydroiodide Monohydrate: Crystal Structure, Optical Second Harmonic Generation, Piezoelectricity and Pyroelectricity.

A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide. The dipeptide is known to show molecular flexibility in different environments, which leads to polymorphism. The crystal structure of the glycyl-L-alanine HI.H2O polymorph is determined at room temperature and indicates that the space group is polar (P21), with two molecules per unit cell and unit cell parameters a = 7.747 Å, b = 6.435 Å, c = 10.941 Å, α = 90°, β = 107.53(3)°, γ = 90° and V = 520.1(7) Å3. Crystallization in the polar point group 2, with one polar axis parallel to the b axis, allows pyroelectricity and optical second harmonic generation. Thermal melting of the glycyl-L-alanine HI.H2O polymorph starts at 533 K, close to the melting temperature reported for cyclo-glycyl-L-alanine (531 K) and 32 K lower than that reported for linear glycyl-L-alanine dipeptide (563 K), suggesting that although the dipeptide, when crystallized in the polymorphic form, is not anymore in its cyclic form, it keeps a memory of its initial closed chain and therefore shows a thermal memory effect. Here, we report a pyroelectric coefficient as high as 45 µC/m2K occurring at 345 K, one order of magnitude smaller than that of semi-organic ferroelectric triglycine sulphate (TGS) crystal. Moreover, the glycyl-L-alanine HI.H2O polymorph displays a nonlinear optical effective coefficient of 0.14 pm/V, around 14 times smaller than the value from a phase-matched inorganic barium borate (BBO) single crystal. The new polymorph displays an effective piezoelectric coefficient equal to deff=280 pCN-1, when embedded into electrospun polymer fibers, indicating its suitability as an active system for energy harvesting.

Atomically Thick Barium Borate for Entangled Multiphoton Generators and Ultraviolet Laser Sources

The upsurge of entangled multiphoton generators and ultraviolet laser sources requires innovative nonlinear optical (NLO) materials. Some atomically thick materials can potentially serve that purpose, but the candidates are few, while the research procedure is not clear. Here, we designed an atomically thick barium borate (BBO) model with a straightforward procedure by exploiting a feature of the corresponding bulk BBO. Specifically, we preserved the planar triangular functional group and sliced the bulk model into atomically thick pieces. As a result, an atomically thick BBO model was brought up to fulfill the requirements of entangled multiphoton generators and ultraviolet laser sources. In general, the present-day requirements of cutting edge laser sources can be met by developing innovative NLO materials as reduced-dimensional derivatives from common NLO bulks.

СИНТЕЗ И ИССЛЕДОВАНИЕ ФИЗИКО-ХИМИЧЕСКИХ И ТЕРМОДИНАМИЧЕСКИХ СВОЙСТВ В СИСТЕМЕ Na2O-BaO-B2O3

38 samples were synthesized in the Na2O-BaO-B2O3 system, some of which were glasses, some crystallized. The degree of interaction of the initial reagents in the synthesis process was controlled by X–ray phase analysis on a DRON-3M diffractometer using CuKa radiation. Crystal phases were identified using X–ray phase analysis on a DRON-3M diffractometer using CuKa radiation and the PDF–2 powder diffractometry database. The following crystalline phases were identified in the crystallized samples: β-BaВ2O4, NaBO2, NaBaB9O15. Density, microhardness, refractive index were measured for glassy samples of the system under study and melting/liquidus temperatures were determined. It is established that the nature of the dependence of the above properties on the content of sodium oxide with a constant content of boron oxide is linear. The study of vaporization processes and thermodynamic properties of the Na2O-BaO-B2O3 system was carried out by differential high-temperature mass spectrometry on the MS–1301 mass spectrometer. The studied samples were evaporated from a twin Knudsen molybdenum effusion cell. The heating of the cell was carried out by electronic bombardment, the temperature was measured with an optical pyrometer EOP–66. It was shown that as a result of the interaction of Na2O, BaO and B2O3 oxides, sodium and barium borates are formed in the condensed phase. It is established that the studied system is characterized by selective evaporation of NaBO2 in the temperature range of 1290–1350 K. The activity values of NaBO2 and B2O3 were determined depending on the composition of the condensed phase at a temperature of 1330 K. The activity of BaB2O4 was calculated using the Gibbs-Dugem equation. The obtained values of the Gibbs mixing energies and excess Gibbs energies indicate significant deviations of the Na2O-BaO-B2O3 system from the ideal behavior.

Energy Transfer in Dy3+ and Tb3+ Double-Doped Barium Borate Glass

In this work, single- and double-doped Dy3+ and Tb3+ barium borate glasses are investigated for their potential as light converters. The density and the absorption coefficient show linearly increasing trends with an increasing lanthanide content. The external quantum efficiency of the double-doped samples is a combination of the respective single-doped samples. The strong energy transfer from Dy3+ to Tb3+ results in an intense Tb3+-related emission, i.e., an intense green luminescence. Thus, excitation at a Dy3+-related wavelength of 452 nm enables a Tb3+-related emission, at which a single-doped Tb3+ sample barely shows any luminescence. Lifetime measurements show that there is not only an energy transfer from Dy3+ to Tb3+, but also vice versa.

Effect of BaO addition on gamma radiation shielding performance of sodium barium borate glasses using FLUKA code and PhyX/PSD platform

Novel Glass system with a formula of xBaO.(30− x).Na2O.70B2O3 (0 ≤x ≤ 30 mol%) have been prepared and examined. The BNaBax-glass structure was used to estimate the influence of BaO addition on the density and molar volume. There is a linear increase in density with increasing BaO concentration. The molar volume varies oppositely. Furthermore, the impact of barium oxide on the gamma and neutron radiation shielding capacities of xBaO.(30− x).Na2O–70B2O3 glasses have been investigated for radiation shielding applications. The μm: coefficient of mass attenuation for BNaBa-0, BNaBa-5, BNaBa-10, BNaBa-15, BNaBa-20, BNaBa-25, and BNaBa-30 glass samples were simulated using the Monte Carlo simulation FLUKA algorithm, in photon energy ranged 0.015MeV–15MeV, the resulting μm simulated results were compared with the Phy-X/PSD platform. The T1/2: half-value layer, λ: mean free path, Zeff: effective atomic number, EBF: exposure, and EABF: energy absorption buildup factors of the BNaBax-glass samples have been estimated. The results presented that a BNaBa-30-glass with a 30-mol.% concentration of BaO has the best gamma and neutron shielding capabilities than the other investigated BNaBax-glass samples.

High-energy, hundred-picosecond pulsed 266 nm mid-ultraviolet generation by a barium borate crystal

Abstract We present a high-energy, hundred-picosecond (ps) pulsed mid-ultraviolet solid-state laser at 266 nm by a direct second harmonic generation (SHG) in a barium borate (BaB2O4, BBO) nonlinear crystal. The green pump source is a 710 mJ, 330 ps pulsed laser at a wavelength of 532 nm with a repetition rate of 1 Hz. Under a green pump energy of 710 mJ, a maximum output energy of 253.3 mJ at 266 nm is achieved with 250 ps pulse duration resulting in a peak power of more than 1 GW, corresponding to an SHG conversion efficiency of 35.7% from 532 to 266 nm. The experimental data were well consistent with the theoretical prediction. To the best of our knowledge, this laser exhibits both the highest output energy and highest peak power ever achieved in a hundred-ps/ps regime at 266 nm for BBO-SHG.

Structural and optical properties of vanadium doped lithium barium borate glasses

This article reports the optical and structural characteristics of (1-x)[50B2O3-30Li2O-20BaO]-xV2O5 glasses, where x has the values as 0, 0.2, 0.4, 0.6, 0.8, 1.0 mol% respectively. Popular technique for glass preparation, melt-quenching has been employed for glass batch preparation. X-ray diffractometric studies provided the confirmation for the amorphous nature of prepared glass samples. Fourier Transform Infra-Red (FTIR) spectroscopy of these glasses show absorption peaks at 574 cm−1, 710 cm−1, 934 cm−1, 1226 cm−1, 1385 cm-1and 2924 cm−1. The peak at 710 cm−1 is arising from B-O-B vibrations. The vibrations in [BO4] groups are responsible for the absorption peak at 900–1000 cm−1. The peaks observed between 1100 and 1400 cm−1 are due to the strong vibrations of B-O-B from [BO3] triangles. UV–Vis NIR spectroscopy of the prepared glass samples was reported and the physical parameters of the glasses have been calculated from the data. The densities of these glass samples were evaluated by using the Archimedes principle, and it was discovered that the density decreased on the successful addition of V2O5 from 3.094 to 3.024 g/cm3. The molar volume was calculated and has been observed that it increased with the addition of V2O5 as 24.059–24.9745. The indirect and direct band gap energies of the glass samples were evaluated byusing UV–Vis NIR spectroscopy, and they were found to be decreased from 4.114 − 3.511 eV and 3.25–2.75 eV respectively. It has been also evaluated how the refractive index varies with thewavelength. The results are discussed concerning the structural refinement in these borate glasses.

Lead Barium Borate Glasses: Optical Properties and Potential Use for Radiation Shielding

Lead Barium Borate Glasses: Optical Properties and Potential Use for Radiation Shielding

Features of noncollinear second harmonic generation by infrared laser pulses with opposite frequency chirps

The features of noncollinear second harmonic generation during the interaction of broadband laser pulses with opposite frequency chirps are considered. The impact of spectral phase mismatch of the interacting pulses on spectrum width and the efficiency of conversion to the noncollinear second harmonic is analyzed on an example of lithium triborate and beta-barium borate crystals.

Wave theory-based fourth harmonic generation of Bessel–Gauss beam by total internal reflection-quasi phase matching in a rectangular slab of beta barium borate

This work presents a theoretical approach to a highly multimode-guided wave-based fourth harmonic (FH) generation method by exploiting a zero-order Bessel–Gauss beam through the total internal reflection quasi phase-matching technique. An anisotropic crystal featuring a rectangular structure of beta barium borate has been used to carry out this analysis. In contrast to the conventional frequency conversion scheme using a Gaussian beam, the projected scheme yields a maximum six times superior efficiency of 6.9547% in a crystal length of nearly 6.3 mm, corresponding to a 266-nm FH wavelength. The analysis has also taken into account optical losses, such as absorption, Goos–Hänchen-shift, surface roughness, and the effect of the nonlinear law of reflection. Finally, a systematic study has been performed to describe the influence of parametric modification, such as variations in slab length and thickness, to provide a more comprehensive picture of the overall analysis.

Spectroscopic analysis of Dy3+ in alkali-varied zinc barium borate glasses for solid-state lighting devices

Spectroscopic analysis of Dy3+ in alkali-varied zinc barium borate glasses for solid-state lighting devices

Fabrication of Beta-Barium Borate Sensing Head for Non-Invasive Measurement of Fluidic Concentration Variations.

In this study, a beta-barium borate sensing head (BBO-SH) was fabricated and evaluated for the measurements of fluidic concentration variations by using a non-invasive technique. The BBO-SH could be coupled to a fluidic container through thin interlayer water in a heterodyne interferometer based on the phase interrogation. To ensure the sensing head's stability, the package of BBO-SH uses the prism and the coverslip bounded with UV glue, which can resist environmental damage due to moisture. After each use, the sensing head could be easily cleaned. The sensitivity of the BBO-SH remained stable after repeated measurements over a period of 139 days. Finally, the achievable measurement resolutions of the concentration and refractive index are 52 ppm and 1 × 10-6 RIU, respectively, for the sodium chloride solution. The achievable measurement resolutions of the concentration and refractive index were 55 ppm and 8.8 × 10-7 RIU, respectively, for the hydrochloric acid solution.

Compositional dependence of thermophysical properties in binary alkaline earth borate melts: Insights from structure in short-range and intermediate-range order

• Thermal conductivity of alkaline earth borate melts is investigated systematically for the first time using transient hot-wire method. • Thermal diffusivity is extrapolated from thermal conductivity, heat capacity and melt density, providing a new approach to thermal diffusivity measurement. • Short-range and intermediate-range order of alkaline earth borate structure is studied using high-resolution MAS-NMR, Raman spectroscopy and XPS for a precise and comprehensive insight into structure-conductivity relationship. • Compositional dependence of thermal conductivity is revealed with the discussion on “boron anomaly” phenomenon in alkaline earth borate melts. In this work, the thermal conductivity of alkaline earth borate melts was measured using hot-wire method from 1323 to 1623 K, and the thermal diffusivity was extrapolated from the thermal conductivity and heat capacity. The compositional dependence of thermophysical properties was interpreted according to the structure in short-range and intermediate-range order. Based on the Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and 11 B magic-angle spinning nuclear magnetic resonance (MAS-NMR) spectra, modifier cation with higher field strength prefers the formation of non-bridging oxygens (NBOs) for the charge compensation at high BO 1.5 / M O ratios. A lower amount of covalent bond and greater isolation of large borate groups lead to a lower thermal conductivity in calcium borate melt compared with strontium and barium borates. But the large size of Ba 2+ encounters difficulty in fitting around B [4] -O-B [4] linkages inside the overcrowded large borate groups when BO 1.5 /BaO = 2.5, promoting the formation of NBOs on the edge of borate groups for the charge compensation of modifier cations and leading to the decline in the thermal conductivity. Thermal conductivity plays a major role in regulating the thermal diffusivity at a given temperature since the compositional dependence of volumetric heat capacity is relatively weak compared with that of thermal conductivity.

Electro-optically tunable cascaded second-order nonlinearity induced (2 + 1)D spatial optical soliton using bulk β-barium borate crystal: a theoretical approach

This paper deals with the development of an effective theoretical approach to generate spatial optical soliton in exceptionally beneficial bulk beta-barium-borate crystal by utilizing cascaded second-order nonlinearity through electro-optic tuning. The proposed methodology paves the way for novel nonlinear optical interactions conceptualized in bulk material depending upon an effective nonlinear refractive index for a broad range of crystal lengths. The development of ( 2 + 1 ) D spatial bright soliton has been analytically demonstrated at 800 nm wavelength of the incident continuous-wave optical radiation, and the implication of tunable electro-optic effect to the crystal’s nonlinear response is also presented here. Involvement of the generalized nonlinear Schrödinger equation has been utilized to develop the necessary and sufficient criteria for self-trapping optical beams considering both linear and nonlinear absorption losses. In conformity with the findings of the simulation, the beam diameter of a generated spatial soliton within this anisotropic crystal is near 56 µm while maintaining precise peak intensity ∼ 0.8 G W / c m 2 .

Optimization and analysis of process parameters of melt quenching technique for multiple performances of rare earth doped barium borate glass synthesis using Taguchi's design and grey relational approach

Glass materials with strong physical, structural, and optical properties are in high demand in today's social and industrial sectors. Researchers have recently established the extensive uses of these widely utilized glassy materials in optoelectronic devices, aerospace, nuclear industries, etc. Optimization usually plays a significant role in the synthesis of material. Hence, this article uses the statistical optimization of multiple process parameters of the melt quenching technique for rare earth doped barium borate glass 60B2O3-(40-X)BaO-XMO (MO-Er2O3/CeO2 and X = 0.5,1.0,1.5 mol percentage)by Taguchi's Design of Experiment. The multiple performance characteristics were studied using Grey relational analysis. An experimental format for preparing the Barium Borate glass was utilized with a standard L9 orthogonal array designed by Taguchi. Grey relational analysis was used to analyze the effects of processing parameters, including melting temperature, the composition of rare-earth oxide, and melting time of glasses on density, refractive index, and indirect bandgap. Analysis of variance (ANOVA) showed the influence of process parameters on the multiple response parameters as directed by the S/N ratio of the response parameter. The prediction of optimal conditions for contributing process parameters to the multiple response parameters was estimated efficiently. Additionally, as compared to the initial conditions, the optimal confirmatory experiment exhibited a considerable improvement in the response parameters (refractive index, density, and indirect bandgap). Grey relational grade and analysis of variance (ANOVA) revealed that melting temperature to be sole factor significantly affecting multiple responses with a 95% confidence level. The objective of the work is to optimize the melt quenching process parameters and their influence on the physical and optical properties of glass for photonic applications. Using this optimization method, melt quenching was found to be the most influential parameter contributing about 73–74% in tuning the desired response parameters. The findings also revealed a very less deviation between the statistically predicted and experimental data of response parameter, with deviation ranging from 0.37 to 2.14%. This good agreement between experimental and predicted values of response parameters indicated the suitability of Taguchi method of optimization for melt quenching technique.

Studies on high power second-harmonic deep-UV generation from a high repetition-rate Cu-HBr laser

This paper presents, for the first time, comprehensive studies on high power second harmonic deep ultraviolet (UV: λ ≈ 255.3 nm) generation from a low temperature, high repetition rate (18 kHz) variant of copper laser (Cu-HBr laser) with different optical resonators (plane–plane resonator and unstable resonators of magnifications 12.5, 50 & 100), pump-beam focussing condition and pump powers. With a type-I, critically phase matched β-barium borate (BBO) crystal as the harmonic generator and different pump average powers (⩽10 W) of the laser, the variation in UV average output powers and its conversion efficiencies were studied. The average UV power and conversion efficiency as high as about 2 W and 26% respectively were achieved. The experimental results were analysed in light of the beam quality attributes of the pump beams vis-à-vis limiting thermal and walk-off effects associated.

Exact Solutions for Vector Phase-Matching Conditions in Nonlinear Uniaxial Crystals

The transcendental equations of vector phase matching are transformed into a fourth-order polynomial equation that admits an analytical solution. The real roots of this equation provide the optical axis orientations that are useful for efficient down-conversion in nonlinear uniaxial crystals. The production of entangled photon pairs is discussed in both collinear and non-collinear configurations of the spontaneous parametric down-conversion (SPDC) process. Degenerate and non-degenerate cases are also distinguished. As a practical example, SPDC processes of type-I and type-II are studied for beta-barium borate (BBO) crystals. The predictions are in very good agreement with experimental measurements already reported in the literature and include theoretical results of other authors as particular cases. Some properties that seem to be exclusive to BBO crystals are reported; the experimental verification of the latter would allow a better characterization of these crystals.

Optimizing the coupling efficiency of spontaneous parametric down-conversion photon pairs into single-mode fibers

Both correlated-mode coupling efficiency and photon pair flux (brightness) of spontaneous parametric down-conversion (SPDC) coupled into single-mode fibers are key parameters for various quantum information science applications. We present an experimental investigation on the optimization of the correlated-mode coupling efficiency and the brightness of frequency-degenerated SPDC photon pairs into single-mode optical fibers. Using photon pairs generated from a type-I phase-matched bulk $\ensuremath{\beta}$-barium borate crystal pumped by a continuous-wave laser, we carefully evaluated both the correlated-mode coupling efficiency and the brightness of SPDC light coupled to a single-mode optical fiber, while continuously changing the focusing of the pump and collection modes, experimenting with Rayleigh lengths from 3 to 280 (for the pump) and 0.2 to 20 (for the collection) times the crystal length. The measured data suggest that the correlated-mode coupling efficiency can be close to unity for any pump focus, however, the optimal Rayleigh length of the collection mode depends on the pump focus parameter, and the brightness can be increased by tightening the pump focus, provided that the Rayleigh length of the collection mode is precisely adjusted. A maximal correlated-mode coupling efficiency of $99.0\ifmmode\pm\else\textpm\fi{}1.3%$ was experimentally achieved. These results will be useful for photonic quantum science and technology using SPDC sources with high heralding efficiencies.

Noncollinear frequency mixing and fourth-harmonic generation of oppositely chirped laser pulses

Highly efficient fourth-harmonic generation of 60 µJ, 25 ps chirped (compressible down to 340 fs FWHM) Yb:KGW laser pulses was demonstrated experimentally utilizing noncollinear opposite chirp frequency mixing in Type I beta-barium borate (BBO) and lithium triborate (LBO) crystals as second-harmonic generators followed by collinear frequency doubling in another BBO crystal as a fourth-harmonic generator. Second-harmonic spectral narrowing by a factor over 100 and output UV pulse energy of 10 µJ were achieved.

FLAME RETARDANT AND ANTIMICROBIAL PAPER COATINGS WITH ROSEMARY OIL AND BARIUM BORATE

Adding an antimicrobial effect to the papers used in the cardboard packaging industry can extend the life of the packed product. Paper, due to its structure, has the property of being ignited quickly. Enhancing the properties of paper, the combination of antimicrobial protection, low flammability and good printability to the paper will expand its usage area in the packaging industry. In this study, barium borate was synthesized in order to impart low flammability to paper. Different combinations of rosemary oil and barium borate were mixed with binding starch in varying amounts, and formulations were prepared. With these mixtures, 80 g/m2 paper was coated using a laboratory-type paper coating machine. The antimicrobial properties of the paper were investigated by performing the disk diffusion antimicrobial test against E. coli and S. aureus bacteria. The Limiting Oxygen Index (LOI) test was performed to determine the low flammability of the paper. Color, gloss, contact angle and surface energy tests were performed for the printability properties of the paper. As a result, the coatings containing formulations of barium borate and rosemary oil, applied to the paper surface, succeeded in imparting antimicrobial and low flammability properties to the papers, while also improving the printability features.