If you want to read the PDF, try requesting it from the authors.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... FTIR XRD Urbach's energy Energy level diagram and CIE chromaticity diagram 5,10,15,20, 25, 30, 35, 40) doped with Sm 3+ ions were prepared by standard method. Present works deals with structural, physical and spectral studies of borosilicate glasses. ...
... But there are only few studies which explore the possibility of using orange red luminescence of Sm 3+ ions in the development of LED's in visible region and also as well as visible optical devices like visible lasers and fluorescent devices. This ion gives orange red emission when doped with borate glasses like lead borate [10], lithium borate [11], lithium zinc borate [12] and lithium yttrium borate glasses [1]. ...
... In this present study Sm 3+ doped borosilicate glasses have been selected with chemical composition (50-x) B 2 O 3 -(10 + x) SiO 2 -10Na 2 O -20 PbO -10 ZnO (x = 0, 5,10,15,20,25,30,35,40) because this glass have low melting point, high thermal stability, high gain solubility, high solubility of RE ions and low refractive index. The objectives of the present study are (i) To prepare Sm 3+ doped borosilicate glasses with varying concentration of SiO 2 by conventional melt quenching technique, (ii) To characterize the samples by XRD, SEM, EDAX, FTIR and TEM, (iii) To calculate the physical and optical parameters with increasing concentration of SiO 2 , (iv) To Study the absorption and fluorescence spectra (v) To compute spectroscopic parameters and (vi) Finally finding the CIE chromaticity coordinates to verify that the prepared glass samples gives orange red emission. ...
Article
Borosilicate glasses with composition (50-x) B2O3 - (10+x) SiO2 - 10 Na2O - 20PbO - 10 ZnO - 0.3 Sm2O3 (where x = 0, 5, 10, 15, 20, 25, 30, 35, 40) doped with Sm³⁺ ions were prepared by standard method. Present works deals with structural, physical and spectral studies of borosilicate glasses. EDAX has been used to establish the elemental composition of these materials. XRD confirms the amorphous nature of the glass materials and also confirmed by the SEM image. Structural information via vibrational modes was provided by FTIR spectra. The increasing and decreasing concentration of SiO2 affects the physical and optical properties of the materials. Among the entire physical and optical properties oxygen packing density (OPD) play important role in defining the structure of the glass samples. For present glass sample OPD decreases with increasing concentration of SiO2, this shows that the structure of glass samples is loosely packed. TEM images give information about smooth surface of the glass material. Absorption spectra have been recorded in the range 400-2500nm and fluorescence spectra have been recorded in visible region at room temperature. With their spectral measurements various spectroscopic parameters have been computed. The value of spectroscopic quality factor is greater than one for present glass samples which shows the stability of the glass samples. The ⁴G5/2 → ⁶H7/2 transition is suitable for reddish-orange laser emission. CIE chromaticity diagram has been recorded for verifying the results of fluorescence.
... But only a few attempts have been made to explore the possibility of using orange-red luminescence of Sm 3+ ions for the development of LEDs in the visible spectral region as well as visible optical devices such as visible lasers and fluorescent devices. Moreover, this ion can exhibit an intense orange-red emission when it is doped in borate glasses such as lead borate, (12) lithium borate (13) and lithium zinc borate glasses. (14) Due to the technological importance of Sm 3+ ions, the present work has been focused on preparation and optical characterization of Sm 3+doped lithium yttrium borate glasses with varying concentration of Sm 3+ ions. ...
... The variation of intensity for both excitations can be attributed due to concentration quenching effects (CQE). (12)(13)(14) To measure the colour of the visible emission that the human eye perceives, the Commission Internationale de l'Eclairage, (CIE) coordinates were calculated. The CIE is the standard reference for defining colours and is obtained by considering the sensitivity of the human eye to different colours (wavelengths). ...
Article
Lithium yttrium borate glasses doped with samarium ions (LiYBO:Sm3+) were prepared by using melt-quenching for different Sm2O3 concentrations. The spectroscopic properties were investigated by using absorption, emission and decay curve measurements. Density and molar volume of LiYBO:Sm3+ glasses increased with increasing Sm2O3 concentration. The glasses absorbed photons in the visible light (VIS) and near-infrared (NIR) regions. For the photoluminescence property, the glasses showed the strongest emission at 600 nm when they were excited by 403 nm photons. The optimum concentration of Sm2O3 in LiYBO glass is 0.50 mol% which exhibited the highest intensity of emission. The lifetime values decreased with increasing Sm3+ ion concentration which is due to energy transfer through cross-relaxation. The non-exponential decay curves are well fitted by the Inokuti-Hirayama model for S=6, indicating that the interaction for cross-relaxation is of the dipole-dipole type.
... Sailaja et al. [13] reported the physical, structural and spectroscopic investigations on Sm 3+ doped ZnO mixed alkaliborate glass. The role of the network modifier PbO in Sm 3+ doped borate glasses has been studied by Krause et al. [14]. Swapna et al. [14] studied the optical properties of Sm 3+ ions doped zinc alumino bismuth borate glasses. ...
... The role of the network modifier PbO in Sm 3+ doped borate glasses has been studied by Krause et al. [14]. Swapna et al. [14] studied the optical properties of Sm 3+ ions doped zinc alumino bismuth borate glasses. Ramteke et al. [16] have investigated the concentration effect of Sm 3+ ions on structural and luminescence properties of lithium borate glasses. ...
Article
A new series of Sm3 + doped alkaliborate glasses have been prepared by melt quenching technique and their structural and spectroscopic properties were analysed employing XRD, FTIR, optical absorption, photoluminescence and decay spectral measurements in order to explore their suitability for photonic applications. The amorphous nature have been confirmed through XRD analysis and the FTIR spectra reveal the presence of fundamental stretching and bending vibrations of the borate networks in the prepared glasses. From the absorption peak positions, bonding parameter (δ) values were calculated to examine the nature of the metal-ligand bond. The optical band gap (Eopt) corresponds to the direct and indirect allowed transitions and the Urbach energies (ΔE) were calculated from the absorption spectra to understand the electronic band structure of the studied glasses. The Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4 and 6) were determined to explore the symmetry of the ligand environment around the Sm3 + ions in the studied glasses. The luminescence spectra exhibit four emission bands in the visible region due to the 4G5/2 → 6H5/2, 6H7/2, 6H9/2 and 6H11/2 transitions. The radiative parameters such as transition probability (A), stimulated emission cross-section (σPE), branching ratios (βR) and radiative lifetime (τR) have been determined from the luminescence spectra using JO theory to ensure the suitability of the studied glasses for optoelectronic applications. The luminescence spectra were characterized through CIE 1931 chromaticity diagram to examine the dominant emission color of the studied glasses. The lifetime values of the Sm3 + doped studied glasses pertaining to the 4G5/2 excited level have been determined through decay curve measurements and the non-exponential decay curves were fitted to the Inokuti-Hirayama model to analyze the energy transfer mechanism between the nearby Sm3 + ions. The obtained results were discussed and compared with the similar reported glasses.
... These glasses have attracted because of their wide range of applications such as waste immobilization of radioactive materials, agricultural applications, hermetic sealing, glass planar optical waveguides, non-linear photonic materials and biomedical applications. Borate glasses are also low melting point, high transparency and high thermal stability [2][3][4][5]. But pure B 2 O 3 glass is not technically interested because it is chemically unstable to atmospheric moisture. ...
... But pure B 2 O 3 glass is not technically interested because it is chemically unstable to atmospheric moisture. However, metal oxides like PbO, ZnO, CdO, CaO, BaO, CuO, MnO, etc., have been added to B 2 O 3 and were found to be good stabilizers of borate glasses [4][5][6]. Amorphous borates generally consist of a random threedimensional network of nearly flat BO 3 triangles with a high fraction of six membered boroxol rings [7]. These structural units are connected by oxygen atoms allowing the B-O-B angle to vary and the twisting out of the plane of the boroxol group to occur [8]. ...
Article
Full-text available
Glasses in the system 0.1CuO-(x-0.1)PbO-(1-x)B2O3 (0.3≤ x ≤ 0.7) were synthesized by using the melt quench technique. A number of studies such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), fourier-transform infrared (FTIR) and Raman spectroscopy, electron paramagnetic resonance (EPR) and dielectric properties (viz., dielectric constant ϵ΄, dielectric loss and ac conductivity σac) are employed to characterize the glasses. The amorphous nature of the glasses was confirmed using XRD while the glass transition temperature (Tg) of glass samples have been estimated from DSC investigation and found that the Tg decreases with increasing PbO content. Raman and FTIR spectroscopy reveals that when increasing lead ions, the tetrahedral [BO4] units are gradually replaced by trigonal [BO3] units. The EPR study leads to determine the local site of Cu²⁺ ions and its transformation with the Pb content in the studied glasses.
... As seen from figure, the decay curves exhibit single exponential nature at lower concentrations (r0.05 mol%) and turn into non-exponential for higher concentrations ( Z0.5 mol%). The lifetime has been estimated for the studied glasses and presented in Table 3 along with the reported glasses [10,26,27]. It is observed that lifetime decreases with increasing the concentration. ...
... Using the above model the energy transfer parameter (Q), critical transfer distance (R 0 ) and donor-acceptor interaction parameter (C DA ) have been evaluated and are presented in Table 3. From Table 3, it is clear that the magnitudes of Q, R 0 and C DA values for SNbKZFSm glasses are found to increase with the increase in Sm 3 þ ion concentration. This type of behavior has also been observed in other reported Sm 2 O 3 -doped glasses [10,26,27]. The increment in these values with the increasing concentration is due to the increase in effective density of donors and acceptors which causes the enhancement of energy transfer through cross-relaxation. ...
Article
Sm2O3-doped fluorosilicate glasses (SiO2+Nb2O5+K2O+ZnF2) were prepared by the melt quenching technique and are characterized through various spectroscopic techniques such as Raman, optical absorption, excitation, emission and decay to derive various spectroscopic properties. Raman analysis has been carried out in order to know the vibrational groups present in the glass matrix. The optical band gap and Urbach energies have been evaluated from the absorption edges of the absorption spectra of 1.0 mol% Sm2O3 doped fluorosilicate glass. The Judd-Ofelt (JO) analysis has been applied to evaluate the intensity parameters, Ωλ (λ=2,4 and 6), for 1.0 mol% Sm2O3 doped fluorosilicate glass. These JO parameters have been used to evaluate radiative properties such as radiative transition probabilities, branching ratios, radiative lifetime and stimulated emission cross-sections for the luminescent levels of Sm3+ ion. The decay curve analysis has been performed for all the glasses in order to know the energy transfer processes between Sm3+ ions. The results indicate that the present glasses could be useful for photonics applications.
... An ideal down-shifting material can absorb the UV light and then reemit it at a longer wavelength where PV devices show higher quantum efficiency. Several reports are available for optical studies of Sm 3+ ions and Sm 3+ -Eu 3+ co-doped ions in different hosts [24][25][26][27][28][29][30][31][32][33][34][35][36]. So far, no work has been reported to study these parameters of Sm 3+ ions and Sm 3+ -Eu 3+ ions co-doped in bismuth boro-tellurite glasses. ...
Article
The effect of host glass composition and co-doping with Eu3+ on the optical properties of Sm3+ has been investigated in bismuth boro-tellurite glasses. The intensity parameters Ωt (t=2,4,6), radiative transition probability (Arad) and radiative lifetimes (τrad) are obtained from optical absorption studies. Excitation spectra show that there exists energy transfer from Sm3+ to Eu3+ and vice versa. From fluorescence studies, fluorescence decay time (τexp), radiative quantum efficiencies (η), branching ratios (β) and peak stimulated emission cross section (σp) are obtained. The highest η of Sm3+ doped bismuth boro-tellurite glasses is found to be 60% and for Sm3+-Eu3+ co-doped glasses, it is 74%. Changing the host glass composition and co-doping with Eu3+ ions, the η of the glasses can be improved. The σp of Sm3+-Eu3+ doped glasses is found to be larger than that of singly doped Sm3+ glasses. Our results indicate that modifying the host glass composition and co-doping with Eu3+ can improve the emission characteristics of Sm3+ ions. Bismuth boro-tellurite glasses with enhanced values for η and σp are suitable for photonic devices and photovoltaic applications.
... In borate glasses Sm 3+ ions were excited in the UV region and several transitions were observed [1,10]. Also Sm 3+ ions -containing borate glasses can be used to obtain enhanced efficiency solar cell [11,12]. ...
Article
In order to study some effects of mixed ions of rare-earth (Sm and/or Dy) on the properties of a glass system, the formula 80% B2O3+ 18% Na2O + (2-x)% Sm2O3 + (x) % Dy2O3; x=0, 0.4, 1.6 and 2 mol. % has been prepared via the well-known melt quenching method. The presence of some structural groups such as BO3, BO4, as well as N4 factor have been scrutinized via FTIR spectra. Absorbance of the prepared solid glass system has been performed by a spectrophotometer in wavelengths between 190 and 1100 nm. Using traditional techniques and standard formulas, the density (ρemp and ρexp), bond density (nB), molar volume (Vm), Fermi energy (EF), refractive index (n), optical bandgap (Eg) have been determined, then the impact of mixed rare-earth oxides (Dy and/or Sm) on the structural and optical properties have been scrutinized. The density, optical bandgap, IR intensity and the refractive index of glass samples shows nonlinear trend, which can be ascribed to the mixed effect of rare-earth cations. However Sm and Dy have been doped with the same percent in the glass system separated and mixed, the effect of Sm ions is obvious than Dy ions.
... In borate glasses Sm 3+ ions were excited in the UV region and several transitions were observed [1,10]. Also Sm 3+ ions -containing borate glasses can be used to obtain enhanced efficiency solar cell [11,12]. ...
Article
In order to study some effects of mixed ions of rare-earth (Sm and/or Dy) on the properties of a glass system, the formula 80% B2O3+ 18% Na2O + (2-x)% Sm2O3 + (x) % Dy2O3; x = 0, 0.4, 1.6 and 2 mol. % has been prepared via the well-known melt quenching method. The presence of some structural groups such as BO3, BO4, as well as N4 factor have been scrutinized via FTIR spectra. Absorbance of the prepared solid glass system has been performed by a spectrophotometer in wavelengths between 190 and 1100 nm. Using traditional techniques and standard formulas, the density (ρemp and ρexp), bond density (nB), molar volume (Vm), Fermi energy (EF), refractive index (n), optical bandgap (Eg) have been determined, then the impact of mixed rare-earth oxides (Dy and/or Sm) on the structural and optical properties have been scrutinized. The density, optical bandgap, IR intensity and the refractive index of glass samples shows nonlinear trend, which can be ascribed to the mixed effect of rare-earth cations. However Sm and Dy have been doped with the same percent in the glass system separated and mixed, the effect of Sm ions is obvious than Dy ions.
... Heavy metal oxide (HMO), such as PbO, which acts both as a glass intermediate and as well as a network modifier depending on its content, improves the refractive index, thermal stability, and considerably lowers the phonon energy of the glasses leading to increased probability of radiative transition rates, thereby it enhances the fluorescence yield [14,18]. The transition metal (TM) ion like ZnO addition to the borotellurite glasses extends ultraviolet (UV) transparency, and improves glass forming ability, moisture resistance, chemical durability, and thermal features with lower devitrification rates [19]. ...
Article
Using melt quenching method, singly Er3+, Dy3+-doped and Er3+/Dy3+-codoped multicomponent borotellurite glasses in the composition (50-x-y) B2O3-10 TeO2-10 PbO-10 ZnO-10 Li2O-10 Na2O-(x) Er2O3- (y) 0.5 Dy2O3 ((x=0.5, 1.0; y=0); (x=0; y=0.5, 1.0); and (x=0.5; y=0.5, 1.0; x=1.0; y=0.5, 1.0)) (mol%) were synthesized. For the fabricated samples, optical absorption, photoluminescence excitation (PLE), photoluminescence (PL), near-infrared (NIR) fluorescence and decay lifetime measurements have been performed. For singly Er3+ and Dy3+-doped samples, Judd-Ofelt (J-O) parameters, Ωt, were calculated following the absorption spectra and the derived Ωt parameters are utilized to predict respective radiative features for these glasses. The PL spectra of the Er3+ and Dy3+ singly doped glasses, excited at 378 nm (Er3+: 4I15/2 → 4G11/2) and 350 nm (Dy3+: 6H15/2→4M15/2,6P7/2), show important green and yellow emission bands at wavelengths 554 nm (Er3+: 4S3/2→4I15/2) and at 574 nm (Dy3+: 4F9/2→6H13/2), respectively. The PL decay curves for Er3+: 4S3/2 level and Dy3+: 4F9/2 level follow single exponential, and non-exponential nature, respectively, for the singly Er3+ and Dy3+-doped samples. For singly 1.0 mol% Er3+ and 0.5 mol% Dy3+-doped samples, the evaluated stimulated emission cross-sections (σPE) for the transitions at λem. = 0550 nm, and 574 nm are equal to 20.923×10-20 cm2 and 0. 526×10-20 cm2, while the gain bandwidths are 3.975×10-25 cm3 and 0.789×10-26 cm3, respectively. For all the Er3+-containing glasses, a broad NIR emission band centered at 1.532 μm (4I13/2→4I15/2) is noticed under both 808 and 980 nm laser diode (LD) excitations, whereas the singly 1.0 mol% Er3+-doped sample shows the highest NIR emission intensity with a full-width at half maximum (FWHM) equal to ~69 and 62 nm, respectively, at these pumping wavelengths. Moreover, the calculated highest (σPE) of 1532 nm NIR emission when pumped by 980 nm is 2.669×10-20 cm2 and gain per unit length is 1.06×10-23 cm2s, for singly 1.0 mol% Er3+-doped glass. Additionally, for Er3+/Dy3+-codoped samples, with the decrement of Er3+: NIR emissions, energy transfer (ET) from Er3+→Dy3+ ions is identified upon both 808 and 980 nm LD pumping. For all Er3+/Dy3+-codoped glasses, the Er3+: 4I13/2 level decay time decreased with increasing Dy2O3 content and the NIR fluorescence decay curves exhibit single exponential nature. Under 980 nm excitation, the computed energy transfer efficiency (ηET) from Er3+: 4I13/2 to Dy3+: 6H11/2 level is 22.9% for the 1.0 Er3+/0.5 Dy3+ (mol%)-codoped glass. Under 808 and 980 nm pumping, the mechanism of the ET processes between Er3+ and Dy3+ ions was discussed in detail. Further, for 1.0 mol% Er3+ singly doped sample, a theoretical gain coefficient value of 17.01 dB/cm is obtained with an excited Er3+ ion fractional factor of 0.6.
... It is generally accepted that glasses containing PbO and/or PbF 2 are classified as toxic raw materials and consequently they are being often eliminated from various practical applications due to their hazardous effect on health and environment. On the other hand these components were established to play important role in glass formation and further strengthening of glass host network [44,45]. Previous investigations indicate that lead oxide is an important glass modifier not only for affecting the chemical and mechanical stabilities of glasses, but also for improving their thermal and optical properties [46]. ...
Article
In this work, luminescence properties of Tb³⁺/Sm³⁺ co-doped lead borate glasses are examined in details. Luminescence spectra of rare earths were measured under different excitation wavelengths. Characteristic luminescence bands corresponding to electronic transitions of terbium and samarium ions were detected under direct excitation of Tb³⁺. The energy transfer from Tb³⁺ to Sm³⁺ ions in lead borate glass occurs through a nonradiative process with an efficiency from 0.6% to 16%, depending on samarium concentration. Luminescence decay curves for the ⁴G5/2 state of Sm³⁺ ions in lead borate glasses were fitted using the Inokuti-Hirayama model. The concentration-dependent luminescence quenching was explained by the non-radiative energy transfer process between the Sm³⁺ ions through the cross-relaxation mechanism. The CIE chromaticity coordinates and correlated color temperatures for Tb³⁺/Sm³⁺ co-doped lead borate glasses are also presented and discussed.
... While titanium oxide (TiO 2 ) can protect optical efficiency for glass systems when used within percent less than 20% [20], this percent was applied in this work. The addition of lead oxide (PbO) to various glass formers results in an extensive glass formation range of 20-80% and an adjustable refractive index [21]. ...
Article
Full-text available
The influence of modifier oxides (TiO2 , ZnO, BaO, and PbO) on the mechanical and radiation shielding properties of boro-tellurate glasses is investigated. Samples with a composition of B2O3-SrO-TeO2-RO (RO represents the modifier oxides) were fabricated using the melt quench method, and their physical, mechanical, and radiation attenuation parameters were reported. For this aim, Monte Carlo simulation was employed to predict the radiation attenuation parameters, while the Makishima-Mackenzie model was adopted to determine the mechanical properties. The tightly packed structure with better cross-linkage density is possessed by the Ti-containing glass (SBT-Ti) system among the titled glass batch. The higher Poisson and micro-hardness values of the SBT-Ti glass indicate its structure's reduced free volume and better compactness. For the glass with PbO, the linear and mass attenuation coefficients are highly increased compared to those glasses doped with TiO2 , ZnO, and BaO. The thinner half-value layer was reported at 0.015 MeV, taking values 0.006, 0.005, 0.004, and 0.002 for samples with TiO2 , ZnO, BaO, and PbO, respectively. SBT-Pb sample (with PbO) has a thinner HVL compared to other fabricated glass samples. The fabricated glasses' thickness (Deq) equivalent to 1 cm of lead (Pb) was reported. The results demonstrated that Deq is high at low energy and equals 11.62, 8.81, 7.61, 4.56 cm for SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb glass samples, respectively. According to the D eq results, the fabricated glasses have a shielding capacity between 30 and 43% compared to the pure Pb at gamma-ray energy of 1.5 MeV. At high energy (8 MeV), the transmission factor values for a thickness of 1 cm of the fabricated samples reach 88.68, 87.83, 85.95, and 83.11% for glasses SBT-Ti, SBT-Zn, SBT-Ba, and SBT-Pb, respectively.
... Several reports are available for Sm 3+ in different hosts (Okada et al. 2014;Krause et al. 2014;Hari Babu et al. 2014;Edgar et al. 2013;Maheshvaran et al. 2011;Pisarska and Pisarski 2011;Jiménez et al. 2011; K o u g h i a e t a l . 2 0 1 1 ; Rada et al. 2 0 1 1 ; Lakshminarayana et al. 2009;Jamalaiah et al. 2009;Sudhakar et al. 2008;Hayakawa et al. 2001), but no work has been done to study the effects of semiconducting NPs on the fluorescence of Sm 3+ ions in borate glasses. In our previous work, we studied the optical absorption of 3 mol% Sm 2 O 3 in lead borate glasses (Saisudha and Ramakrishna 1996). ...
Article
Full-text available
The effect of glass composition and the presence of CdSe/ZnSe nanoparticles (NPs) on the optical absorption and fluorescence of Sm-doped lead borate glasses are studied. Three sets of glass samples xPbO:(99.5-x) B2O3:0.5Sm2O3, x = 29.5–69.5 mol%, xPbO:(96.5-x) B2O3:0.5Sm2O3: 3CdSe/ZnSe, x = 36.5, and 56.5 mol% are prepared. NPs are grown by annealing these glasses just below the glass transition temperature. Average size of both types of NPs increases with annealing time; however, CdSe NPs grew to a larger size range (2 to 20 nm) compared to ZnSe NPs (1 to 16 nm). We analyzed the hypersensitive transition, intensity parameters, radiative transition probability, stimulated emission cross section (σp), and the area ratio of the electric dipole/magnetic dipole transitions of Sm³⁺. The intensity parameters show a minimum at 11 h annealing for 36.5 mol% and a maximum for the same annealing duration in 56.5 mol% PbO containing CdSe NPs. The σp for 56.5 mol% of PbO with CdSe NPs is found to be a maximum when the average NP size is around 14 nm. ZnSe NPs containing glasses also show significant changes in σp when the average particle size is ~16 nm, for 36.5 mol% PbO. Our results suggest that the optical properties of Sm³⁺ in lead borate glasses are sensitive to its electronic environment which can be modified by varying the base glass composition and/or incorporating large NPs of CdSe/ZnSe. The large σp values that we observe for some of the glass compositions make them attractive materials for photonic devices and photovoltaic applications. Graphical abstract
... This band appears due to the luminescence of Pb 2+ . 27,28 The decrease of the Pb-related emission band is mostly due to concentration quenching. The excited atoms then undergo successive non radiative relaxation to 4 G 5/2 from which the emission origi- nates. ...
Article
Samarium-doped lead oxyflouroborate glasses of 60 B2O3- xPbO- (40-x)LiF where (x=0-30 mol%) with 3×1020 ions/cm3 of Sm2O3, were prepared by melt quenching. UVVis absorption, photo luminescence (PL) and cathode luminescence (CL) spectroscopies were used to study the effect of varying PbO content on the spectroscopic properties of these samarium-doped glasses. The absorption of the UV-edge shifts toward higher wavelengths, not only because of higher polarizability of lead ions, but also because of the strong allowed s-p transition of Pb2+. Judd-Ofelts parameters were determined and indicate that the asymmetry around Sm3+ ions increases with increasing PbO content. Ω2 probes the asymmetry by the ratio of intensity of the hypersensitive transition (6H9/2) to that of purely magnetic (6H5/2) transition. Furthermore, an increase in the spectroscopic quality factor (Ω4/Ω6) was observed with increasing PbO content which indicates that these glasses have the potential to be used as efficient active laser glasses. The calculated energy transfer parameter increases with increasing PbO content. Also, stark splitting increases with increasing PbO concentrations. FWHM of the CL emission peaks and stark splitting, are found to be much larger than that in PL. This was explained by the high electric field generated from the exciting electron pulses.
... Today, inorganic borate glasses doped with lanthanide (Ln 3þ ) ions are significant well-known materials in modern photonics because of their wide spread applications in the development of lasers [1], optical fibers [2], infrared to visible up converters and luminescent lamp [3], flat displays [4] and optical communication systems [5]. Usually, borate glass systems are preferred owing to their significant properties such as high transparency, low melting point, high temperature stability and good solubility of RE 3þ ions [6,7]. But, these glasses unfortunately suffers from low refractive index and high phonon energy (~1400 cm_1) [8]. ...
Article
The Dy³⁺-doped lithium gadolinium silica borate glasses with composition (in mol%) 40Li2O:15Gd2O3:5SiO2: (40-x)B2O3:xDy2O3, x = 0.01, 0.1, 0.5, 1.0, 2.0 were prepared by melt quenching technique and characterized through absorption and emission spectra, CIE chromaticity coordinates and decay rate analysis. Judd-Oflet parameters have been calculated for lithium gadolinium silico borate glass and used for the derivation of radiative properties for excited luminescent levels of Dy³⁺ ions. The feasibility of white light generation have been evaluated by the yellow-to-blue emission intensity ratios and CIE chromaticity coordinates as a function of Dy³⁺ concentration. The non-exponential decay rates are well-fitted to Inokuti-Hirayama model for S = 6. The perceived non-exponential decay nature and life time quenching have been ascribed to the energy transfer between excited and unexcited Dy³⁺ ions through dipole–dipole interaction. The CCT values for the present studied glasses obtained in the 4584-4235 K at λexc = 387 nm. These CCT values are below the warm CCT (i.e CCT 4000 K). The reasonably good luminescence properties of LGSiBDy10 glass indicates the potentiality of the title of glass to be applied as lasing medium for white light generation.
... Heavy metal oxide (HMO), such as PbO, which acts both as a glass intermediate and as well as a network modifier depending on its content, improves the refractive index, thermal stability, and considerably lowers the phonon energy of the glasses leading to increased probability of radiative transition rates, thereby it enhances the fluorescence yield [14,18]. The transition metal (TM) ion like ZnO addition to the borotellurite glasses extends ultraviolet (UV) transparency, and improves glass forming ability, moisture resistance, chemical durability, and thermal features with lower devitrification rates [19]. ...
Article
Using melt quenching method, singly Er³⁺, Dy³⁺-doped and Er³⁺/Dy³⁺-codoped multicomponent borotellurite glasses in the composition (50-x-y) B2O3-10 TeO2-10 PbO-10 ZnO-10 Li2O-10 Na2O-(x) Er2O3- (y) 0.5 Dy2O3 ((x=0.5, 1.0; y=0); (x=0; y=0.5, 1.0); and (x=0.5; y=0.5, 1.0; x=1.0; y=0.5, 1.0)) (mol%) were synthesized. For the fabricated samples, optical absorption, photoluminescence excitation (PLE), photoluminescence (PL), near-infrared (NIR) fluorescence and decay lifetime measurements have been performed. For singly Er³⁺ and Dy³⁺-doped samples, Judd-Ofelt (J-O) parameters, Ωt, were calculated following the absorption spectra and the derived Ωt parameters are utilized to predict respective radiative features for these glasses. The PL spectra of the Er³⁺ and Dy³⁺ singly doped glasses, excited at 378 nm (Er³⁺: ⁴I15/2 → ⁴G11/2) and 350 nm (Dy³⁺: ⁶H15/2→⁴M15/2,⁶P7/2), show important green and yellow emission bands at wavelengths 554 nm (Er³⁺: ⁴S3/2→⁴I15/2) and at 574 nm (Dy³⁺: ⁴F9/2→⁶H13/2), respectively. The PL decay curves for Er³⁺: ⁴S3/2 level and Dy³⁺: ⁴F9/2 level follow single exponential, and non-exponential nature, respectively, for the singly Er³⁺ and Dy³⁺-doped samples. For singly 1.0 mol% Er³⁺ and 0.5 mol% Dy³⁺-doped samples, the evaluated stimulated emission cross-sections (σPE) for the transitions at λem. = 0550 nm, and 574 nm are equal to 20.923×10⁻²⁰ cm² and 0. 526×10⁻²⁰ cm², while the gain bandwidths are 3.975×10⁻²⁵ cm³ and 0.789×10⁻²⁶ cm³, respectively. For all the Er³⁺-containing glasses, a broad NIR emission band centered at 1.532 μm (⁴I13/2→⁴I15/2) is noticed under both 808 and 980 nm laser diode (LD) excitations, whereas the singly 1.0 mol% Er³⁺-doped sample shows the highest NIR emission intensity with a full-width at half maximum (FWHM) equal to ~69 and 62 nm, respectively, at these pumping wavelengths. Moreover, the calculated highest (σPE) of 1532 nm NIR emission when pumped by 980 nm is 2.669×10⁻²⁰ cm² and gain per unit length is 1.06×10⁻²³ cm²s, for singly 1.0 mol% Er³⁺-doped glass. Additionally, for Er³⁺/Dy³⁺-codoped samples, with the decrement of Er³⁺: NIR emissions, energy transfer (ET) from Er³⁺→Dy³⁺ ions is identified upon both 808 and 980 nm LD pumping. For all Er³⁺/Dy³⁺-codoped glasses, the Er³⁺: ⁴I13/2 level decay time decreased with increasing Dy2O3 content and the NIR fluorescence decay curves exhibit single exponential nature. Under 980 nm excitation, the computed energy transfer efficiency (ηET) from Er³⁺: ⁴I13/2 to Dy³⁺: ⁶H11/2 level is 22.9% for the 1.0 Er³⁺/0.5 Dy³⁺ (mol%)-codoped glass. Under 808 and 980 nm pumping, the mechanism of the ET processes between Er³⁺ and Dy³⁺ ions was discussed in detail. Further, for 1.0 mol% Er³⁺ singly doped sample, a theoretical gain coefficient value of 17.01 dB/cm is obtained with an excited Er³⁺ ion fractional factor of 0.6. Following the explored visible and NIR optical results, the synthesized glasses might be useful for visible and NIR fiber lasers application.
Article
Series of Eu³⁺-doped lead-free germanate and borate glasses were synthesized. The MO glass modifiers (M = Ca, Sr or Ba) were partially or totally substituted by MF2 in chemical composition. In contrast to samples modified by CaO/CaF2 or SrO/SrF2, the germanate glass samples containing BaO and/or BaF2 are fully amorphous, while the lead-free borate glasses are fully amorphous, independently from glass modifiers. Effect of glass modifiers on spectroscopic properties of Eu³⁺ were systematically investigated. For that reason, excitation and emission spectra of Eu³⁺ ions in examined systems were registered. Based on the emission spectra, ratio of integrated luminescence intensity of the ⁵D0 → ⁷F2 transition to that of the ⁵D0 → ⁷F1 transition (R factor) was calculated. Moreover, the luminescence decay curves were collected and the luminescence lifetimes of the ⁵D0 excited state of Eu³⁺ ions were determined in function of MF2 concentration.
Article
Full-text available
Glasses, glass ceramics and polycrystalline compositions based on ZnO, P 2 O 5 and B 2 O 3 have both scientific and technological importance because of their useful applications. Doping with rare earth elements not only leads to a rearrangement in the structure, but also to variation in the optical, magnetic and electrical properties. We have synthesized samarium doped ZnO-rich borophosphate materials of composition xSm 2 O 3 – (72.31–x)ZnO – 9.69P 2 O 5 – 18B 2 O 3 , where x = 0, 0.25, 0.5, 0.75, 1 mol%. Samarium doped ZnO-rich borophosphate compositions were annealed with a target to obtain nanocrystalline structures. Materials were characterized by x-ray powder diffrac-tion (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and photoluminescence (PL) measurements. The results obtained show that synthesized materials are predominantly amorphous, with the presence of nano and polycrystalline structures in heat-treated samples. The structure and morphology of the obtained materials were evidenced by powder XRD data, SEM imaging and thermal DSC analysis. All different content Sm doped samples show PL peaks in the range of 550–650 nm belonging to Sm 3+ ions.
Article
The aim of this paper is to investigate the photon, charged particles, fast and thermal neutrons absorption characteristics and dose rates of Sm³⁺ doped borosilicate glasses containing Na2O–PbO–ZnO via theoretical method and simulation code. The linear attenuation coeficients of SBNPZS4 glasses are the highest whereas the mass attenuation coefficients of SBNPZS1 glasses are the highest in the present SBNPZS glasses. The SBNPZS4 has the lowest half value layer and mean free path values among the SBNPZS glasses and compared standard shielding materials therefore SBNPZS4 has the better photon absorption characteristics. The effective atomic number, effective electron density, mass energy-absorption coefficient, specific gamma ray constant, and gamma dose rate values change as SBNPZS4<SBNPZS3<SBNPZS2<SBNPZS1. The ranges of SBNPZS glasses for charged particles modify as SBNPZS4<SBNPZS3<SBNPZS2<SBNPZS1. Both fast neutron removal cross section and total cross section for thermal neutron vary in order of SBNPZS1<SBNPZS2<SBNPZS3<SBNPZS4 hence SBNPZS4 owns the highest fast and thermal neutron absorpiton characteristics. Consequently, SBNPZS glasses can be suggested and developed as photons, neutrons and charged particles shielding materials.
Article
Series of lead-free borate glasses with different oxide modifiers and lanthanide ions were prepared. The effect of oxide modifiers MO (M = Ca, Sr, Ba) on spectroscopic properties of trivalent Ln3+ (Ln = Eu, Er, Pr) were systematically investigated. Especially, the luminescence spectra of Ln3+-doped lead-free borate glasses are presented and discussed in relation to the impact of selective components (CaO, SrO and BaO). Several spectroscopic parameters, such as the fluorescence intensity ratio R/O (Eu3+) and measured luminescence lifetimes for the 5D0 (Eu3+), 4I13/2 (Er3+) and 1D2 (Pr3+) excited states of lanthanide ions were analyzed in details. The research proved that spectroscopic properties of trivalent Ln3+ depend significantly on kind of presence oxide modifiers MO (M = Ca, Sr, Ba) in glass host matrices.
Article
Alkali-borosilicate glass samples doped with 0.04 - 0.7 mol % of neodymium oxide (20SiO2-(50-x) H3BO3-20Na2CO3-10ZnO-xNd2O3) have been prepared by the melt quenching method. Thermoluminescence (TL) properties such as: dose response, thermal fading, minimum detectable dose and reproducibility of the gamma irradiated samples were investigated. Kinetic and trapping parameters such as trap depth, kinetic order and frequency factor were studied by using the glow curve shape, initial rise and computerized glow curve de-convolution (GCDC) methods. Among the studied concentrations, the obtained results showed that alkali-borosilicate glass doped with 0.15 mol % neodymium oxide is the most sensitive one. This glass composition has a good linear TL gamma dose response over a wide dose range of 0.5-1000 Gy, as well as low fading and excellent reproducibility. These obtained features recommend the new prepared glass for many radiation detection applications.
Article
Sm³⁺ (0.1, 0.2, 0.3, 0.4 & 0.5 wt%) doped zinc phosphate glasses have been prepared by melt quenching technique. Their physical, as well as optical properties, have been studied. The UV–Vis absorption spectroscopy was carried on in the wavelength range of 400–700 nm which reveals five absorption bands at 406 nm, 445 nm, 478 nm, 533 nm, and 572 nm respectively. The direct bandgap is found to be 2.42–2.47 eV while the indirect bandgap is 2.30–2.34 eV. Urbach energy is calculated to be 0.4237–0.4445 eV. The other parameters like dielectric susceptibility, metallization, refractive index, oxygen packing density, etc., have also been studied.
Article
In this study, the optical, thermoluminescent, structural, and physical characteristics of samarium doped manganese potassium borate glasses were analyzed using diffuse reflectance spectroscopy, thermoluminescence (TL), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy techniques. The glasses were obtained using the well-known melt–quenching process. The XRD patterns confirmed the non-crystalline characteristics of the prepared glasses and numerous structural groups were identified in the glasses based on the FTIR spectra. Physical and optical parameters were evaluated to study their responses to different Sm³⁺ concentrations. The indirect and direct band gaps were evaluated based on the Tauc's plots. The TL glow curves for the glasses were analyzed after irradiation with different gamma ray doses (10 Gy–10 kGy). Kinetic parameters including the frequency factor and activation energy were determined using the peak shape method.
Article
Intense multi-peak red fluorescence emissions of Sm3+ are exhibited in alkaline-earth borate (LKZBSB) glasses under UV radiation. The spontaneous emission probabilities Arad corresponding to the 4G5/2→6HJ (J=5/2, 7/2, 9/2 and 11/2) transitions are derived to be 24.74, 129.72, 117.03 and 32.23 s−1, respectively, and the relevant stimulated emission cross-sections σem are 0.77×10−22, 4.46×10−22, 5.05×10−22 and 1.38×10−22 cm2, confirming the effectiveness of red luminescence in Sm3+-doped LKZBSB glasses. Quantitative characterization through the evaluation of absolute spectral parameters reveals that the quantum yield of Sm3+-doped LKZBSB glasses is as high as 13.29%. Furthermore, with the introduction of Ce3+, the effective excitation wavelength range and the emission intensity of Sm3+ in LKZBSB glasses are remarkably expanded and improved by a maximum sensitization factor of 9.02 in the UVB region. These results demonstrate that the present glass system has promising potential as an efficient UV→visible photon conversion layer for the enhancement of solar cell efficiency, including appealing applications in outer space.
Article
Full-text available
Fluorophosphate and fluoroaluminate glasses doped with trivalent samarium were evaluated as sensors of x-ray radiation for microbeam radiation therapy at the Canadian Light Source using the conversion of trivalent Sm3+ to the divalent form Sm2+. Both types of glasses show similar conversion rates and may be used as a linear sensor up to ∼150 Gy and as a nonlinear sensor up to ∼2400 Gy, where saturation is reached. Experiments with a multi-slit collimator show high spatial resolution of the conversion pattern; the pattern was acquired by a confocal fluorescence microscopy technique. The effects of previous x-ray exposure may be erased by annealing at temperatures exceeding the glass transition temperature Tg while annealing at TA < Tg enhances the Sm conversion. This enhancement is explained by a thermally stimulated relaxation of host glass ionic matrix surrounding x-ray induced Sm2+ ions. In addition, some of the Sm3+-doped glasses were codoped with Eu2+-ions but the results show that there is no marked improvement in the conversion efficiency by the introduction of Eu2+.
Article
Full-text available
Room temperature visible and near infrared optical absorption and emission spectra of Sm3+-doped lead borate titanate aluminum fluoride (LBTAF) glasses with molar composition (50�x) PbO�30H3- BO3�10TiO2�10AlF3�xSm2O3 (x ¼ 0.1, 0.5, 1.0 and 2.0) have been analyzed. Energy parameters for the 4f5 electronic configuration of Sm3+: LBTAF glasses have been evaluated using free-ion Hamiltonian model. The experimental oscillator strengths of absorption bands have been used to determine the J–O parameters. Fluorescence spectra were recorded by exciting the samples with 402 nm. Using the J–O parameters and luminescence data, the radiative transition probabilities (AR), branching ratios (bR) and stimulated emission cross-sections (se) were obtained. The decay curves of 4G5/2-6H7/2 transition exhibit single exponential for lower concentration (0.1 mol%) and non-exponential for higher concentrations. This concentration quenching has been attributed to the energy transfer through cross-relaxation between Sm3+ ions. From the values of the radiative parameters, it is concluded that 1.0 mol% Sm3+-doped LBTAF glass may be used for laser active medium with emission wavelength at 600 nm.
Article
Full-text available
Using the photoluminescence from GeGaSe:Er to pump GeGaS:Er, we examine the efficiency of light trapping. By measuring the photoluminescence decay time in powdered materials with varying particle size, we are able to exclude the influence of light trapping and to pinpoint the effect of self-quenching. The critical concentrations of Er for efficient self-quenching are determined by fitting experimental data to existing models. These values are found to be much larger than the concentrations inducing the formation of Er-clusters.
Article
The density and refractive index of single and mixed alkali borate glass systems have been measured and used to calculate the molar volume, molar refractivity and molar refractivity of oxygen ion in order to investigate the configurational changes that might be induced in the glass structure as the constituent alkali ion is gradually replaced by another. A slight deviation from linearity was observed only in the density composition relation for glasses containing 20 mol% (Na2O–K2O). The deviation significantly increases with increasing (Na2O–K2O) content but does not exceed 1% which suggests that the observed deviation does not result from a large scale structural rearrangement of the local network of mixed alkali borate glasses.
Article
Sm3+-doped barium borate glasses are investigated for their potential as a superstrate for CdTe solar cells. The influence of the Sm3+ conversion efficiency and the Sm2O3 doping level on the short circuit current density of a CdTe solar cell is analyzed. CdTe solar cells with CdS layer thicknesses of 45 and 300 nm are evaluated. A 3.2 mm thick, 2 mol% Sm2O3- doped glass superstrate enables a relative increase in the short circuit current density of approximately 1.4% and 2.9% for a 45 and 300 nm CdS buffer layer, respectively, assuming 100% Sm3+ conversion efficiency.
Article
Lead borate and lead alumino borate glasses in the systems xPbO(.)(100-x)B2O3 (0 less than or equal to x less than or equal to 75 mol%) and xPbO(95-x)B2O3,5Al(2)O(3) (0 less than or equal to x less than or equal to 80 mol%), respectively, have been prepared and investigated by Raman spectroscopy. Using the Martin-Brenig model, structural correlation lengths were determinated from Boson peak positions of temperature reduced Raman spectra and transversal sound velocities. Vv polarized spectra contain information about the nature of the PbO component within the network.
Article
Borate glasses and borate glass ceramics are good candidates as a matrix material for fluorescent ions like samarium. The chosen network modifier influences the fluorescence efficiency of the incorporated rare earth ion. Sm3+-doped lithium, sodium, barium and lead borate glasses were examined with respect to their fluorescence properties and potential use as a down-converting top layer of a solar cell.
Article
The luminescence of Pb2+ in several calcium borates is reported. The different luminescence spectra can be assigned by considering the oxygen coordination. The energy levels of the asymmetrically coordinated Pb2+ ion do not seem to be influenced by the orientation of the BO3 triangles, since the absorption and Stokes shift of the emission band are more or less similar for the differently structured borates. The presence of a ‘free’ oxygen ion shifts the excitation and emission bands to lower energies. The splitting of the excitation bands seems to originate from the influence of the crystal field rather than from the Jahn-Teller effect.
Article
Dolomites of the type MZr(BO3)2 (M = Ca, Sr, Ba) are reported. The Pb2+ ion is an efficient luminescent activator in these compounds. The Stokes shift is large. The Tb3+ ion is sensitized by Pb2+ (Rc ~ 9 Å). The Ti4+ ion shows at 300 K medium efficiency due to thermal quenching.
Article
The effect of host glass composition on the optical absorption spectra of Nd3+, Sm3+, and Dy3+ in lead borate glasses, with PbO contents varying from 30 to 70 mol %, has been analyzed using Judd-Ofelt theory and the compositional dependence has been determined for the hypersensitive bands. Judd-Ofelt intensity parameters Ωt (t=2,4,6), and the radiative transition probabilities. The variation of Ω2 with PbO content has been attributed to changes in the asymmetry of the ligand field at the rare-earth (R) site (due to the structural changes) and to changes in R-O covalency, whereas the variation of Ω6 has been related to the variation in R-O covalency. The radiative transition probabilities of the rare-earth ions are large in lead borate glasses suggesting their suitability for laser applications. © 1996 The American Physical Society.
Article
Nonradiative decay of excited rare-earth ions by multiphonon emission has been investigated in a series of oxide glasses. Various rare-earth electronic levels were selectively excited by short-duration laser pulses and multiphonon relaxation rates were determined from measurements of fluorescence rise and decay times. Time resolution for fluorescence measurements was 3 nsec, so excited states were probed for which the decay was predominantly nonradiative. Excited states of Nd3+, Er3+, and Tm3+ with energy gaps to the next-lower J state ranging from 1300 to 4700 cm-1 were studied. The multiphonon relaxation rates for each glass investigated exhibited an approximately exponential dependence on energy gap. Evidence of breakdown of this dependence was observed in the region of small energy gaps. The measured temperature dependences of the decay rates establish that the relaxation occurs predominantly by excitation of the highest-frequency vibrations associated with stretching modes of the glass network former. Borate, silicate, phosphate, germanate, and tellurite glasses were studied. From Raman spectra, the highest-frequency vibrations for these glasses ranged from 700 to 1400 cm-1. The corresponding multiphonon relaxation rates for a given energy gap differed by three orders of magnitude. The strength of the ion-phonon coupling was found to be approximately equal for all glasses.
Article
Fluorescence spectra and decay properties of the level of the Sm3+ ions have been measured in two glass systems of lithium borate and lithium fluoroborate glasses as a function of pressure up to 27.2 and 25.9 GPa, respectively, at room temperature. With an increase in pressure continuous redshifts of the → (J = 9/2,7/2, and 5/2) multiplet transitions as well as progressive increases in the magnitude of the splittings for these transitions are observed. Decay curves in both the systems exhibit perfect single exponential behavior at ambient pressure and become nonexponential at higher pressures accompanied by a moderate decrease in lifetimes. The nonexponential decay curves fit well to the Inokuti–Hirayama [ M. Inokuti and F. Hirayama, J. Chem. Phys. 43, 1978 (1965) ] model for S = 6, indicating that the interaction for cross relaxation is of dipole-dipole type. The decrease in lifetime of the level in both the systems with pressure is explained as resulting from the increase in the crystal-field strength felt by the Sm3+ ions due to volume reduction accompanied by a simultaneous increase in the electronic transition probabilities.
Article
The decay of donor luminescence in a rigid solution when modified by electronic energy transfer by the exchange mechanism is treated theoretically. The rate constant for the elementary process of energy transfer is taken to be of the Dexter form, const exp(−2R/L), where R is the donor—acceptor distance and L is a positive constant. Calculations are made of the yield and decay time of the donor luminescence as functions of the acceptor concentration. The resulting relationship among the above quantities enables one to analyze experimental data in a quantitative manner, and thereby to obtain information about an intermolecular exchange interaction. As an example of such an analysis, Ermolaev's data on triplet—triplet transfer between some aromatic molecules are compared with our results, and very good agreement is found with a choice of the single parameter L.
Article
Spectral characterization of Sm3+-doped phosphate (PKBAS: P2O5 + K2O + BaO + Al2O3 + Sm2O3) and fluorophosphate (PKBFAS: P2O5 + K2O + BaO + BaF2 + Al2O3 + Sm2O3) glasses through absorption, emission and decay curves are presented. The observed bands in absorption spectra, responsible for transitions from ground state to various excited states, are assigned and analyzed using free-ion Hamiltonian (HFI) model. Radiative properties are predicted using Judd–Ofelt theory. Experimental branching ratios and lifetimes of the 4G5/2 level are compared with theoretical values. The decay curves of Sm3+-doped phosphate and fluorophosphate glasses are perfectly single exponential for lower concentration (0.01 mol%) and gradually change to non-exponential for higher concentrations. The analysis of non-exponential behavior of decay curves through Inokuti–Hirayama model indicates that the energy transfer between Sm3+ ions is of dipole–dipole type. Our systematic analysis on decay measurements reveals that energy transfer mechanism strongly depends on concentration as well as glass composition.
Article
Glasses in the system $xPbO:(100- x)B_2O_3 (22\leq x\leq 85$ mol%) have been studied by Raman spectroscopy with a view to understand the effect of PbO on the borate network. The conversion of three-fold to four-fold coordinated boron takes place primanly by incorporation of $BO_4$ into boroxol rings in the form of pentaborate and diborate units. For high lead content, back conversmn of four to three coordinatmn of borons occurs and the network consists primardy of pyroborate, orthoborate and metaborate groups.
  • N A Sharaf
  • A A Ahmed
  • A F Abbas
N.A. Sharaf, A.A. Ahmed, A.F. Abbas, Phys. Chem. Glasses 39 (2) (1998) 76.
Far infrared spectrum of lead borate glasses: evidence for the simultaneous occurrence of ionic and covalent Pb-O bonds. The structure of non-crystalline materials
  • P Tarte
  • M J Portier
P. Tarte, M.J. Portier. Far infrared spectrum of lead borate glasses: evidence for the simultaneous occurrence of ionic and covalent Pb-O bonds. The structure of non-crystalline materials, P.H. Gaskell (Ed.), 1977, p. 227.
  • W L Konijnendijk
  • H Verweij
W.L. Konijnendijk, H. Verweij, J. Am. Ceram. Soc. 59 (1976) 459.
  • G Blasse
  • S J M Sas
  • W M A Smit
G. Blasse, S.J.M. Sas, W.M.A. Smit, J. Materials Chem. Phys. 14 (1986) 253.
  • S Vahedi
  • G Okada
  • B Morrell
  • E Muzar
  • C Koughia
  • A Edgar
  • C Varoy
  • G Belev
  • T Wysokinski
  • D Chapman
  • S Kasap
S. Vahedi, G. Okada, B. Morrell, E. Muzar, C. Koughia, A. Edgar, C. Varoy, G. Belev, T. Wysokinski, D. Chapman, S. Kasap., J. Appl. Phys. 112 (2012) 073108.
  • C Koughia
  • S O Kasap
C. Koughia, S.O. Kasap, Opt. Express 16 (2008) 7709.
  • B N Meera
  • A K Sood
  • N Chandrabhas
  • J Ramakrishna
B.N. Meera, A.K. Sood, N. Chandrabhas, J. Ramakrishna, J. Non-Cryst. Solids 126 (3) (1990) 224.
  • M Inokuti
  • F Hirayama
M. Inokuti, F. Hirayama, J. Chem. Phys. (1965)1978.
  • C K Jayasankar
  • V Venkatramu
  • P Babu
  • T H Tröster
  • W Sievers
  • G Wortmann
  • W B Holzapfel
C.K. Jayasankar, V. Venkatramu, P. Babu, T.h. Tröster, W. Sievers, G. Wortmann, W.B. Holzapfel, J. Appl. Phys. 97 (2005) 093523.