Bismuth Borate Glasses Research Articles

Structural and optical properties of barium titanate modified bismuth borate glasses

Glass samples with composition (70B2O3–29Bi2O3–1Dy2O3) modified with Barium titanate (BT), where BT is added in different successive weight percents, have been synthesized by conventional melt quenching technique. X-ray diffraction studies were performed in order to confirm the amorphous nature of the samples. The density of the samples has been found to decrease with an increase in the BT content, whereas an opposite trend has been observed in the molar volume. The analysis of FTIR and Raman spectra of the samples depicts that the glass network is built up of mainly BiO6, BiO3, BO3 and BO4 units. Its detailed analysis also revealed that the glass structure depends upon the amount of BT in the glass matrix and hence it acts as a modifier in the glass network. Introduction of BT into the glass matrix leads to the conversion of BO3 trigonal units into BO4 tetrahedral units, which results in a decrease in the degree of disorder in the glass network and makes the glass system more stable. The values of Urbach energy obtained for the prepared samples also confirmed the decrease in disorder in the glass network. The optical absorption measurements carried out for well-polished samples show a decrease in optical band gap energy with an increase in BT content whereas the molar refractivity shows the reverse trend. The Hydrogenic excitonic model applied to the studied glasses suggested that the present glass system favors direct transitions. The metallization criterion of the presently studied samples suggests that the prepared glasses may be potential candidates for nonlinear optical applications.

Tb3+ doped Zinc Alumino Bismuth Borate glasses for green emitting luminescent devices

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with terbium (Tb3+) ions with a chemical composition 20ZnO–10Al2O3–(10−x)Bi2O3–60B2O3−xTb2O3 (x=0.1, 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0mol%) were prepared by a conventional melt quenching method and studied their optical absorption, photoluminescence and decay spectral properties. The Judd–Ofelt (J–O) parameters evaluated from the experimental oscillator strengths were used to measure the radiative properties for the prominent luminescent transitions of Tb3+ ions such as 5D4→7F6, 7F5, 7F4 and 7F3. The effect of Tb3+ ion concentration on the luminescence process observed in the visible region was discussed in detail. The emission spectra recorded for all the ZnAlBiB glasses doped with Tb3+ ions, show an intense peak in green region at 542nm. The stimulated emission cross-section, branching ratios and quantum efficiency values evaluated for green emission (5D4→7F5) suggests the utility of these glasses for green luminescence applications. It was found that, within the concentration range investigated, 2.5mol% of Tb3+ doped ZnAlBiB glass is most suitable for green luminescence applications at 542nm in principle.

Luminescence characterization of Eu3+ doped Zinc Alumino Bismuth Borate glasses for visible red emission applications

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Eu3+ ions have been prepared by rapid melt quenching technique and characterized for their luminescence behavior through various spectroscopic techniques such as absorption, excitation, emission, decay profiles and confocal image measurements at room temperature. From the measured absorption spectra, the bonding parameters (δ) were evaluated to find the nature of bonding between Eu3+ ions with its surrounding ligands in these ZnAlBiB glasses. The emission spectra of Eu3+ ions in ZnAlBiB glasses excited at 410nm (CW laser) show the characteristic of Eu3+ ions with more intense visible red emission corresponding to 5D0→7F2 transition. This intense visible red emission is further confirmed by the confocal luminescence images recorded for all the ZnAlBiB glasses. Judd–Ofelt (J–O) parameters estimated from the emission spectral information are used to estimate the important radiative properties such as transition probability (AR), branching ratios (βR) and emission-cross sections for the prominent emission levels. The large stimulated emission cross-sections and branching ratios observed for ZnAlBiB glasses suggest the utility of these glasses in visible red region of the electromagnetic spectrum. The CIE chromaticity coordinates evaluated from the emission spectra and the confocal images recorded for all the ZnAlBiB glasses also indicates that, these glasses at higher concentration of Eu3+ ions are aptly suitable for intense red emission at 613nm corresponding to 5D0→7F2 transition.

Density, Electrical and Optical Properties of Yttrium-Containing Tellurium Bismuth Borate Glasses

60B2O3-30Bi2O3-(10 − x) TeO2-xY2O3 mol.% (x = 0, 0.1, 1, 2 and 5) glasses have been prepared by the conventional glass-melting technique. The influence of Y2O3 on the density, optical and electrical properties of the glass was investigated. The density decreased whereas the molar volume increased with increasing Y2O3. Optical transmission in the ultraviolet (UV) spectral region indicated that the values of direct and indirect optical band gap energies increased, which was attributed to structural changes induced by the addition of Y2O3. Urbach energy values decreased with increasing the Y2O3, which was attributed to a decrease in the broadening due to static disorder-related parts. Fourier transform infrared (FTIR) spectra revealed that the addition of Y2O3 transforms BO4 to BO3 and BiO3 to BiO6 groups. The decrease in the dc and ac electrical conductivities was attributed to the formation of [BiO6] units which leads to a decrease in acceptor levels of Bi5+ sites. The electric modulus formalism indicated that the conductivity relaxation at different frequencies was a temperature-independent dynamic process. The full width at half-maximum (FWHM) of the normalized modulus decreases with increasing Y2O3 content, suggesting that the decrease of the Y ion–ion distance increases the interaction between the Y ions.

Fabrication and analysis of new bismuth borate glasses containing cement kiln dust

New bismuth alkali borate glasses based on cement kiln dust (CKD) have the chemical formula xCKD–(100−x) (B2O3–Bi2O3–Na2O–BaO) were fabricated by the conventional melt quenching technique. The glasses were analyzed by room temperature FTIR, density and ultrasonic measurements to study the effect of CKD on the structure and the mechanical parameters of the glasses. The physical parameters such as the density and the elastic moduli of the studied bismuth alkali borate network are sensitive to the concentration of CKD. The results indicate a creation of CaO6 and SiO4 on one hand and a mutual conversion between BO4 and BO3 structural units on the other hand. These units control the short-range order of the glasses and the non-linearity decrease of the density and the increase of the ultrasonic parameters. The results were interpreted in terms of the vibrations of the various structural units and the type of bonding between different atoms.

Structural and Optical Properties of Ho<sup>3+</sup> Doped ZnO-Bi<sub>2</sub>O<sub>3</sub>-B<sub>2</sub>O<sub>3</sub> Glasses

Ho3+ doped zinc bismuth borate glasses of the composition 10ZnO : 30Bi2O3 : (60-x)B2O3 : xHo2O3 (where x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0 mol%) were fabricated by conventional melt quenching technique. In order to understand the role of Ho2O3 in these glasses, the density, molar volume and optical spectra were investigated. The molar volume decreases with an increase in Ho2O3 content, which is attributed to the structure becomes more compacted. The absorption spectra of Ho3+ doped in zinc bismuth borate glass correspond to several bands, which are assigned from the ground state, 5I8 to 5G5 (420 nm), 5G6 + 5F1 (451 nm), 5F2 + 5F4 (538 nm), 5F5 (643 nm) and 5I5 (1152 nm). Moreover, the optical basicities were also theoretically determined.

Ho3+‐doped strontium–aluminium–bismuth–borate glasses for green light emission

Strontium-aluminium-bismuth-borate glasses (SAlBiB) doped with different concentrations of Ho(3+) were prepared using conventional melt quenching technique and their structural and optical properties investigated. X-ray diffraction and scanning electron microscopy analysis were used to study the structural properties. Optical properties were studied by measuring the optical absorption and visible luminescence spectra. The Judd-Ofelt (J-O) theory was applied to evaluate J-O intensity parameters, Ω(λ) (λ = 2, 4 and 6). Using J-O intensity parameters, radiative properties such as spontaneous transition probabilities (A(R)), branching ratios (β(R)) and radiative lifetimes (τ(R)) were determined. From the emission spectra, a strong green emission nearly at 549 nm corresponding to the transition, (5)S2 ((5)F4)→(5)I(8) was observed. Emission peak positions (λ(P)), effective bandwidths (Δλ(eff)) and stimulated emission cross-sections (σ(p)) were calculated for the observed emission transitions, (5)F3 →(5)I(8), (5)S2((5)F4)→(5)I(8) and (5)F5 →(5)I(8) of Ho(3+) in all the glass matrices. Chromaticity color coordinates were calculated using the emission spectra. The experimental results suggest that SAlBiB glass matrix with 1.5 mol% of Ho(3+) has better emission properties.

Comparative spectral and shielding studies of binary borate glasses with the heavy metal oxides SrO, CdO, BaO, PbO or Bi2O3 before and after gamma irradiation

This work aims to compare the experimental shielding behavior of some prepared binary borate glasses with SrO, CdO, BaO, PbO or Bi2O3 towards successive gamma irradiation by investigating their combined optical and FTIR spectral measurements before and after gamma irradiation. Optical spectra of all the samples reveal strong UV absorption which is related to the presence of unavoidable trace iron impurities (Fe3+ ions) contaminated within the raw materials which were used for the preparation of the studied glasses. Additional near visible bands are observed in the two lead borate and bismuth borate glasses due to characteristic absorption of Pb2+ and Bi3+ ions. Gamma irradiation causes varying responses depending on the type of glass. Bismuth borate glass shows highly marked shielding towards successive gamma irradiation while lead borate glass reveals resistance in low dose (4Mrad) and produces induced defects at high dose (8Mrad). The other glasses show obvious generation of induced defects upon gamma irradiation. FTIR spectra of the glasses reveal vibrational modes characteristic to combined presence of triangular and tetrahedral borate units in their specific different wavenumbers besides the presence of interfering structural PbO and BiO linkages in the lead borate and bismuth borate glasses. Gamma irradiation produces limited changes in the FTIR spectra specifically the intensity of some vibrational modes while the bismuth borate glass has proved to be the best radiation-shielding candidate when comparing the combined spectral results after successive gamma irradiation.

Optical studies of Sm3+ ions doped Zinc Alumino Bismuth Borate glasses

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of samarium (Sm3+) ions were prepared by using melt quenching technique and characterized for their lasing potentialities in visible region by using the techniques such as optical absorption, emission and emission decay measurements. Radiative properties for various fluorescent levels of Sm3+ ions were estimated from absorption spectral information using Judd–Ofelt (JO) analysis. The emission spectra and con-focal photoluminescence images obtained by 410nm laser excitation demonstrates very distinct and intense orange–red emission for all the doped glasses. The suitable concentration of Sm3+ ions in these glasses to act as an efficient lasing material has been discussed by measuring the emission cross-section and branching ratios for the emission transitions. The quantum efficiencies were also been estimated from emission decay measurements recorded for the 4G5/2 level of Sm3+ ions. From the measured emission cross-sections, branching ratios, strong photoluminescence features and CIE chromaticity coordinates, it was found that 1mol% of Sm3+ ions doped ZnAlBiB glasses are most suitable for the development of visible orange–red lasers.

Gamma radiation shielding and optical properties measurements of zinc bismuth borate glasses

In this work, the zinc bismuth borate (ZBB) glasses of the composition 10ZnO:xBi2O3:(90−x)B2O3 (where x=15, 20, 25 and 30mol%) were prepared by the melt quenching technique. Their radiation shielding and optical properties were investigated and compared with theoretical calculations. The mass attenuation coefficients of ZBB glasses have been measured at different energies obtained from a Compton scattering technique. The results show a decrease of the mass attenuation coefficient, effective atomic number and effective electron density values with increasing of gamma-ray energies; and good agreements between experimental and theoretical values. The glass samples with Bi2O3 concentrations higher than 25mol% (25 and 30mol%) were observed with lower mean free path (MFP) values than all the standard shielding concretes studied. These results are indications that the ZBB glasses in the present study may be developed as a lead-free radiation shielding material in the investigated energy range.

Emission analysis of CdO–Bi2O3–B2O3 glasses doped with Eu3+ and Tb3+

This article reports on the emission properties of cadmium bismuth borate (CdBiB) glasses as a function of doping concentrations of Eu3+ and Tb3+ ions. The functional groups present in the glasses have been identified by analyzing FT-IR spectra. The emission spectra of Eu3+ and Tb3+:CdBiB glasses have shown reddish green emissions at 616nm (5D0→7F2) under the excitation at 465nm and at 547nm (5D4→7F5) under the excitation at 485nm, respectively. The Judd–Ofelt (J–O) theory was applied to evaluate the J–O intensity parameters from the absorption and the emission spectra; by using the J–O intensity (Ωλ) parameters, spontaneous emission transition probability (A), total radiative transition rate (AT), radiative lifetime (τR) and branching ratios (β) of the various emission transitions have been computed for both Eu3+ and Tb3+:CdBiB glasses. The quenching behavior in the emission intensity with increased concentration of Eu3+ and Tb3+ was observed, which could be useful for optimizing the compositions toward practical applications.

Effect of Nd2O3 addition on structure and characterization of lead bismuth borate glass

The effect of different contents of Nd2O3 on the thermal transition temperature, density and structure of 25 Bi2O3 – 25 PbO – 50 B2O3 has been investigated using X-ray diffraction (XRD), differential thermal analysis (DTA), infrared spectrophotometer (FTIR) and optical absorption. The amorphous phase has been identified based on X-ray diffraction analysis. The neodymium oxide plays the role as a glass-modifier and influences on BO3↔BO4 conversion. The observed increase in Tg with Nd2O3 reflects an increase in bond strength. The decrease of the density and the increase of the molar volume with the addition of Nd2O3 contents attributed to an increase in the number of Non-bridging oxygen (NBOS). The optical absorption results are indicating the higher covalency of the Nd–O bond for glass containing 2mol% of Nd2O3. In addition, a lowest covalency is observed in glass with 1mol% Nd2O3. In addition, it is considered necessary in the construction of compact and efficient laser source.

Visible red, NIR and Mid-IR emission studies of Ho3+ doped Zinc Alumino Bismuth Borate glasses

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses doped with different concentrations of Holmium were prepared by conventional melt quenching technique. The glassy nature of these glasses has been confirmed through the XRD spectral measurements. The FTIR spectra recorded for undoped glass revealed the information related to the functional groups involved in the host glass. Optical absorption, excitation and photoluminescence spectra of these glasses have been recorded at room temperature. The Judd–Ofelt theory has been applied successfully to characterize the absorption spectra of the ZnAlBiB glasses. From this theory various radiative properties such as radiative transition probability (AR), radiative lifetimes (τR), branching ratios (βR) and spectroscopic quality factor (χ) for the prominent emission levels 5F5→5I7, 5F5→5I8 and 5I7→5I8 have been evaluated. The photoluminescence spectra revealed the quenching of luminescence intensity beyond 1.0mol% of Ho3+ ion concentration in ZnAlBiB glasses. To investigate the lasing potentiality of 5F5→5I7, 5F5→5I8 and 5I7→5I8 transitions, the effective band width (Δλp) and the stimulated emission cross-section (σse) were determined. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for visible red laser emission in principle.

Visible luminescence characteristics of Sm3+ doped Zinc Alumino Bismuth Borate glasses

Zinc Alumino Bismuth Borate (ZnAlBiB) glasses at different compositions doped with 1mol% of Sm3+ ions were prepared by using the melt quenching technique and investigated by XRD, optical absorption, emission and decay curve analysis to understand the visible luminescence of these glasses. From the absorption spectra the JO parameters are evaluated and are used to calculate the radiative properties such as transition probability, radiative lifetime, branching ratio and absorption cross-sections for various fluorescent levels of Sm3+ ions. The emission spectra of Sm3+ ions doped ZnAlBiB glasses show two intense emission bands 4G5/2→6H7/2 (orange) and 4G5/2→6H9/2 (red) for which the stimulated emission cross-section and branching ratios are evaluated to understand the potentiality of these materials as visible lasers. The decay profiles for the 4G5/2 fluorescent level of Sm3+ doped ZnAlBiB glasses have been recorded to measure the quantum efficiency (η) of these glasses. The strong visible emissions, large stimulated emission cross-sections, high branching ratios and good quantum efficiencies observed for the present ZnAlBiB glasses suggest the suitability of these glasses as laser and photonic devices operating in visible region.

Correlation of ion dynamics with characteristic length scales and network structural units in bismuth borate glasses

Ion dynamics in lithium bismuth borate conducting glasses have been reported in wide composition and temperature ranges. The activation energy for the dc conduction has been analysed using Anderson-Stuart model and a correlation between the dc conductivity and the doorway radius has been predicted. The characteristic length scales for ion dynamics, such as mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively. A direct connection between the ion dynamics and the characteristic length scales and the network structural units have been established.

Effect of Addition TiO<sub>2</sub> on Bi<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub>-B<sub>2</sub>O<sub>3</sub> Glasses

Bismuth titanium borate glasses in compositions xTiO2 : (30-x)Bi2O3 : 70B2O3 (with x is in mol%, varying from 0% to 10%) were fabricated by the conventional melt quenching technique. The effect of TiO2 on the physical and spectroscopic properties of bismuth borate glasses have been carried out by means of density and UV-Visible spectroscopy measurement techniques. The density and molar volume of all glasses are found to change depend on TiO2 substitution. The fundamental absorption edges for all glasses have been identified using the theory proposed by Davis and Mott. The optical band gap (Eg) is found to decrease with increase in TiO2 content.

Synthesis and Luminescence Properties of Sm<sup>3+</sup> in Bismuth Borate Glass

In this research present the results of the analysis of Sm3+ ions doped bismuth borate glasses. Optical measurements such as absorption, excitation and emission profiles have been carried out. Glasses with the chemical compositions (50-x)B2O350Bi2O3xSm2O3 (x = 0.0, 0.5, 1.0, 1.5, 2.50 and 2.5 mol%) were prepared using a conventional melt-quenching method. The emission spectrum of Sm3+ doped bismuth borate glasses has shown the emission transitions of to 4G5/26H 5/2 (563 nm), 4G5/26H 7/2 (598 nm), 4G5/26H9/2 (644 nm). Energy level schemes relating to the emission mechanisms involved in Sm3+ glasses have been given.

Photoluminescence Investigation of Dy<sup>3+</sup> Ions in Bi<sub>2</sub>O<sub>3</sub>-B<sub>2</sub>O<sub>3</sub> Glasses

In this work, the photoluminescence properties of bismuth borate glass doped with Dy3+ have been studied. Glasses were prepared using the glass composition formula 30Bi2O3 : (70-x)B2O3 : xDy2O3, where x is 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 mol%. Glass samples were fabricated by the use of the normal melt-quenching technique at the melting temperature of 1,100 °C at 3 hour time intervals. Glass samples were annealed at the temperature of 500 °C at 3 hour time intervals to remove thermal strain. From photoluminescence study, the emission spectra (excited at 451 nm) were observed three emission peaks, which are assigned to 4F9/26H15/2 (484 nm), 4F9/26H13/2 (574 nm), and 4F9/26H11/2 (661 nm) transitions, respectively. The luminescence intensities of all glasses are comparable and the strongest intensity peak at 574 nm was obtained.

Reddish-orange emission from Pr3+ doped zinc alumino bismuth borate glasses

Praseodymium doped Zinc Alumino Bismuth Borate (ZnAlBiB) glasses were prepared by melt quenching technique and characterized by optical absorption and emission studies. The glassy nature of these glasses has been confirmed through XRD spectral measurements. From the absorption spectra, the Judd–Ofelt intensity parameters Ωλ (λ=2, 4 and 6) and other radiative properties like transition probability (AR), radiative lifetimes (τR) and branching ratios (βR) have been evaluated. Emission spectra were measured for different concentrations of Pr3+ ions doped glasses by exciting the glasses at 445nm. The intensity of Pr3+ emission spectra increases from 0.1 to 1mol% and beyond 1mol% concentration quenching is observed. The suitable concentration of Pr3+ ions in ZnAlBiB glasses to act as a good lasing material at reddish-orange wavelength (604nm) region has been discussed by measuring the emission cross-sections for the intense emission transition 1D2→3H4. The CIE chromaticity co-ordinates were also evaluated from the emission spectra for all the glasses to understand the suitability of these materials for reddish-orange emission. From the measured emission cross-sections and CIE chromaticity co-ordinates, it was found that 1mol% of Pr3+ is aptly suitable for the development of visible reddish-orange lasers.

Structural study of bismuth borosilicate, aluminoborate and aluminoborosilicate glasses by 11B and 27Al MAS NMR spectroscopy and thermal analysis

Glasses of bismuth borosilicates, aluminoborates and aluminoborosilicates were prepared by melt quenching and characterized by density measurements, 11B and 27Al Magic Angle Spinning (MAS) Nuclear Magnetic Resonance (NMR) spectroscopy, and Differential Scanning Calorimetry (DSC). Increase in silica concentration increases density without any change in the fraction of tetrahedral borons (N4) in the borosilicate glass network, whereas increase in alumina concentration in aluminoborate and aluminoborosilicate glasses drastically reduces density and N4. 27Al MAS NMR measurements revealed that Al ions are in four, five and six fold coordination with oxygen and about 47% of these are in [5]Al and [6]Al structural units, the concentration of the latter species decreases by adding silica in the glass network. Higher cation field strength of Bi3+ generates very large concentration of non-bridging oxygens, which act as charge balancing centers in the glass network. DSC measurements found that alumina and silica incorporation in bismuth borate glasses do not produce any systematic changes in the glass transition temperature but the tendency towards crystallization decreases steadily.