Absorption Spectra Of Glasses Research Articles

Physical and Optical Properties of Zinc Barium Borotellurite Glasses Doped with CeF3

Abstract Zinc barium borotellurite glasses with the composition 10ZnO-30BaO-30B2O3-(30-x)TeO2 -CeF3 have been fabricated by using the melt-quenching technique at 1,150 °C for 1.5 hours. The doping concentration of the CeF3 was varied from 0.00 - 1.50 mol%. The glass samples were characterized through physical and optical properties were investigated. The results showed that the density of the glasses increased whereas the molar volume decreased with increasing of CeF3 concentrations. The prepared glasses are determined FTIR spectroscopy has been observe the structural modification of (TeO4) trigonal bipyramid structural units. The optical absorption spectra of glasses were measured in the UV-VIS and NIR range of 250-2,500 nm. The intensity of all absorption bands increased with increasing CeF3 contents. In addition, the optical band gap was decreased with increasing of CeF3

Photoluminescence properties and energy transfer investigations of Gd3+ and Sm3+ co-doped ZnO–BaO–TeO2 glasses for solid state laser application

The physical, optical, photoluminescence properties of (54-x) TeO2 − 10ZnO − 35BaO − 1Sm2O3 − xGd2O3, where 0 ≤ x ≤ 3 (mol %) are investigated in this research. Five samples of glass were produced by the normal melt quenching process. The evidence indicates that the density of glass increased with increasing of Gd2O3. The molar volume and refractive index investigations have been used to consider the physical properties and optical properties of the produced glass system. Physical parameters such as polaron radius, inter-ionic radius and field strength for Sm3+/Gd3+ ions have been evaluated. The absorption spectra of glass contain peaks at 358, 404, 948, 1,085, 1,235, 1,385, 1490 and 1535 nm corresponding to the transitions from 6H5/2 to 4D3/2, 6P3/2, 6F11/2, 6F9/2, 6F7/2, 6F5/2, 6F3/2, and 6H15/2, respectively. The emission spectra of glass show four bands at found and attributed to 563, 604, 646 and 709 nm by excitation at 275 nm. Judd-Ofelt parameters and radiative properties was investigated for 53.5TeO2 − 10ZnO − 35BaO − 1Sm2O3 − 0.5Gd2O3 glass. Energy transfer characteristics was observed in the present glasses. The emission intensity of Sm3+ increased with increasing of Gd2O3 concentration until 2 mol %, while the luminescence lifetime decreases with increasing of Gd2O3 content.

The Physical and Optical Properties of Glasses from Local Sand in Nakhon Pathom Province

In this work, local sand in Mueang and Kamphaeng Saen district of Nakhon Pathom Province were used as raw material in glasses. The glass samples were prepared in formula 45SiO2 : 20B2O3 : 10BaO : 25Na2O by melt and quenching technique. Four difference raw SiO2 of glass samples were prepared by local general (GM) and fine sand of Mueang size 150 μm (GM150) and local general (GK) and fine sand of Kamphaeng Saen size 150 μm (GK150). These samples were investigated physical and optical properties to compare with glass from high silica commercial grade (GS). The density and refractive index values of glass from local sand have close to reference glass around 2.6700-2.6896 g/cm3 and 1.5376-1.5391, respectively. The Vicker’s hardness of glasses were in good acceptable values around 393.2-465 HV. While, the optical properties of glasses from local sand were differed to reference glass. The absorption spectra of glasses from local sand were occurred the contamination of Fe2+ and Fe3+ ions in wavelength of 440 nm and 1,050 nm. This contamination of iron oxide was obtained from local sand. However, this experiment demonstrates that possibility of utilizing local sand in glass production.

Production and investigation of black glasses as absorber materials: Transition metal ions doped silicate glasses

A 60% SiO2-20% Na2O-18% CaO-2% Al2O3 glass structure was prepared and 20 wt% CoO was incorporated to this base glass to produce black glass by melt-quench technique. The effects of transition metal ions on the physical, thermal and optical properties of the black glass were investigated as V2O5 and CuO were doped to its structure. The density values of the glasses range from 2.59 g cm−3 to 2.89 g cm−3. As the doping ratio of transition metal ions increased, the glass transition temperature (Tg) values increased but the melting temperatures (Tm) did not show this regular change. The thermal stability and glass forming ability values of all glasses were also calculated. The absorption spectra of glasses were taken in the wavelength range 200–1100 nm. The values of optical band gap energy were determined from Mott and Davis's model. The refractive index values were calculated with the help of the optical band gap results by use of the Dimitrov-Sakka relation. Optical dielectric constants were also calculated by using the refractive index values. All results were elucidated with regard to the structural changes obtained effect of the transition metal ions. The variation in physical, thermal and optical properties was related to the non-bridging oxygen change in the structure.

Investigation of Luminescence Properties of Dy<sup>3+</sup> Doped Alkaline Earth Oxides Barium Phosphate Glasses

In this work, the optical and luminescence properties of Dy2O3 doped barium phosphate glass with different alkaline earth oxides (MgO, CaO and SrO) have been investigated. The glass samples were prepared by the melt-quenching technique at the melting temperature of 1200 °C. The absorption spectra of glasses were recorded in the ultraviolet, visible and near infrared (UV-Vis-NIR) region. The absorption bands centered at 385, 424, 452, 472, 754, 803, 901, 1093, 1273 and 1683 nm, respectively have been observed. The emission spectra of glass samples centered at 482, 574, 662 and 751 nm, respectively have been observed with 350 nm excitation wavelength. The result of radioluminescence spectra were slightly different with photoluminescence spectra. The coordinate of emitting color (x, y) for 350 excitation wavelength is 0.3781 and 0.4252, respectively which is located in white light region of CIE diagram.

Properties of erbium luminescence in barium borophosphate glasses

Barium borophosphate glasses doped with five concentrations of Er2O3 were prepared by a melted-quenching process. The properties of glasses have been investigated through density, molar volume, absorption and emission spectra measurements. The obtained density and the calculated molar volume values increased with increasing Er2O3 contents. The absorption spectra of glasses were found to have eleven absorption bands at 362 (4I15/2→4G9/2), 379 (4I15/2→4G11/2), 407 (4I15/2→2G9/2+4H9/2), 450 (4I15/2→4F5/2), 488 (4I15/2→4F7/2), 521 (4I15/2→2H11/2), 544 (4I15/2→4S3/2), 652 (4I15/2→4F9/2), 803 (4I15/2→4I9/2), 978 (4I15/2→4I11/2) and 1537 nm (4I15/2→4I13/2). At 521 nm excitation wavelength, the photoluminescence spectra showed highest peak around 1530 nm (4I13/2→4I15/2). The emission intensity depends on Er3+ ion concentration and shown higher emission intensity with increasing concentration of Er2O3.

Photoluminescence Properties of CaO-BaO-P<sub>2</sub>O<sub>5</sub> Glass Systems Doped with Sm<sup>3+</sup>

This paper reports on physical, optical and photoluminescence properties of Sm3+doped calcium barium phosphate (CaO: BaO: P2O5: Sm2O3) glass systems. The glass samples have been prepared by the melt-quenching technique at 1200°C. It was found that the density of glasses tended to increase with increasing of Sm2O3 concentration. While, the molar volume of glasses tended to decrease with increasing of Sm2O3 concentration higher than 0.1 mol%. The absorption spectra of glasses were recorded in the ultraviolet visible near infrared (UV-Vis-NIR) region. The absorption bands centered at 374, 402, 416, 438, 473, 527, 946, 1083, 1236, 1382, 1483, 1531 and 1977 nm, respectively have been observed. The emission spectra of glass samples centered at 561, 597, 643 and 704 nm corresponding to the energy levels from 4G5/2 to 6H5/2, 6H7/2, 6H9/2 and 6H11/2, respectively have been observed with 402 nm excitation wavelength.

Spectral Investigations of Dy<sup>3+</sup>-Doped Gd<sub>2</sub>O<sub>3</sub>-CaO-P<sub>2</sub>O<sub>5</sub> Glasses

Dy3+-doped phosphate glasses of the compositions 20Gd2O3 : 10CaO : (70-x)P2O5 : xDy2O3, where x = 0.05, 0.10, 0.50, 1.00 and 1.50 mol% have been prepared by melt quenching technique and characterized by optical absorption, emission spectra and decay curve analysis. All the transitions in the absorption spectra are originated from the 6H15/2 ground level to the various excited states and these are intra configuration (f-f) transitions. The observed twelve absorption bands centered at 349, 362, 387, 425, 451, 473, 750, 800, 895, 1089, 1266 and 1676 nm are assigned to 6P7/2, 4P3/2, 4F7/2, 4G11/2, 4I15/2, 4F9/2, 6F3/2, 6F5/2, 6F7/2, 6F9/2, 6H9/2 and 6H11/2 transitions, respectively. The absorption spectra of glasses increase with increase in Dy3+ ion concentrations. The emission spectra of Dy3+-doped glasses are observed to be centered at 483, 573, 662 and 752 nm originated from the 4F9/2→6H15/2, 4F9/2→6H13/2, 4F9/2→6H11/2 and 4F9/2→6H9/2 transitions, respectively under excitation at 349 nm. The highest emission intensity of Dy3+-doped glass is 0.50 mol% due to concentration quenching effect. The experimental lifetimes are found to decrease when Dy3+ ion concentrations increased due to energy transfer process between Dy3+ ions.

Physical, Optical and Luminescence Properties of Er<sup>3+</sup>-Doped Bismuth Borosilicate Glasses

Er3+-doped bismuth borosilicate glasses (Bi2O3+B2O3+SiO2+Er2O3) glasses doped with different Er2O3 concentrations (0, 0.50, 1.00, 1.50, 2.00, 2.50 mol%) have been prepared by melt quenching technique and their physical, optical and luminescence properties have been studied. The density of glasses showed the highest value at 4.7358 g/cm3 with 1.00 mol% of Er2O3. The optical absorption spectra of glasses were observed seven bands at 488, 523, 543, 654, 801, 975 and 1529 nm which assigned to the transitions 4I15/2→4F7/2, 2H11/2, 4S3/2, 4F9/2, 4I9/2, 4I11/2 and 4I13/2, respectively. The emission spectra of glasses were also investigated and discussed in term of energy level of Er3+ ion in glass matrices.

PbS quantum dot doped glass prepared by sol-gel method

Na2O-B2O3-SiO2 glasses doped with semiconductor PbS quantum dots were fabricated via a sol-gel routine in this paper. The influence of different heat treatment on microstructure of glass were made, and characterization of the micro-crystals doped in glass matrix were made by varies methods. The result of N2 adsorption-desorption shows that the diameter of pores in the interior of glass diminishes, with increasing temperature, and the pores totally disappear at last. IR spectra indicate that network structure of glass is form at low temperature, and becomes compact at higher temperature. The PbS crystals are found in the glass matrix by both X-ray photoelectron spectroscopy (XPS) and high-resolution transmission electron microscopy (HRTEM), and the average size of the crystallites is 3.5nm in diameter. Comparing with the bulk PbS, the absorption edge in the optical absorption spectra of glass containing PbS quantum dots exhibits a blue shift and shows obvious quantum size effect. The nonlinear refractive index (γ) of the glass doped with PbS micro-crystals was determined by Z-scan technology to be -1.6×10-11cm2/GW.

Radiation-induced color centers in γ-irradiated glasses in the Na2O-Nb2O5-P2O5 system

The specific features of the induced optical absorption spectra of glasses in the 45Na2O · xNb2O5 · (55 − x)P2O5 system with Nb2O5 contents x = 5, 10, 20, 25, 30, and 35 mol % are investigated as functions of the irradiation dose and the heat treatment time. The spectra are decomposed into Gaussian components with the use of computer processing. It is revealed that the glass composition and the irradiation dose affect the number, type, and parameters of the bands associated with the PO 4 2− hole-type centers, electron-type color centers of the phosphate matrix, [Nb(5+)−] one-electron centers, and [Nb(5+)−-O-Nb(5+)−] two-electron centers. The inference is made that heat treatment at temperatures close to the glass transition point T g leads to the formation of groupings with a structure similar to structural motifs of NaNbO3 crystals. It is demonstrated that these groupings are responsible for the induced optical absorption in the near-IR spectral range.

Rare earths in nanocrystalline glass–ceramics

The optical spectroscopic analysis of rare earth ions in transparent oxyfluoride glass–ceramics obtained from SiO2–Al2O3–PbF2–CdF2 based precursor glasses is presented. The oscillator strengths of the optical transitions were measured from the absorption spectra of glasses and glass–ceramics doped with rare earth ions. The results were analysed in the framework of the Judd–Ofelt theory giving the values of the three Ω2, Ω4 and Ω6 intensity parameters over the rare earth series. On the other hand, high efficient infrared-to-blue upconversion has been observed in Tm3+–Yb3+ codoped glass and glass–ceramic compared to the Tm3+ single doped matrices. The contributions to the upconversion process of the rare earth ions in the nanocrystalline and in the vitreous phase of the glass–ceramics have been distinguished. Finally, laser action in Nd3+-doped glass–ceramic has been studied. Losses due to UV and visible upconverted emissions inside the laser cavity have been also estimated.

OPTICAL ABSORPTION AND ESR SPECTRAL STUDIES ON COPPER-DOPED LEAD-CADMIUM GLASSES

The electron spin resonance and optical absorption spectra of PbO-CdO glasses containing 1 mole% CuO have been investigated at room temperature. The optical absorption spectra of all glass samples have exhibited a broad asymmetric absorption band, which corresponds to a d–d transition of Cu 2+ ions. The prepared glass samples have been analyzed as a function of the photon energy. The results are interpreted based on the optical absorption spectral profiles and also the edge values upon the application of Davis and Mott's theory. From the ESR spectral features, the spin Hamiltonian parameters have been evaluated. The bonding coefficients were obtained, in order to elucidate the information on the Cu 2+ ligand bond nature.

Specific features of the induced absorption spectra of fluoroaluminate glasses doped with samarium ions

The induced optical absorption spectra of γ-irradiated fluoroaluminate glasses doped with Eu3+ and Sm3+ ions are investigated. It is shown that Sm3+ ions in fluoroaluminate glasses are protector ions contributing to the suppression of induced absorption in the optical absorption spectra of the studied glasses. It is revealed that the induced optical absorption spectra of the glass samples heat treated at T = 583°C contain two absorption bands with maxima at 300 and 480 nm, which correspond to radiation-reduced (Sm3+)–. The concentration of color centers produced by γ-radiation in fluoroaluminate glasses is estimated. It is demonstrated that prolonged heat treatment of the glass at T = 638 K brings about the decay of (Sm3+)– centers followed by the destruction of the samples.

Problems of spectrophotometry of glass-forming melts: II. A technique for measuring the absorption spectra of glasses and melts in the red and near-infrared ranges at temperatures from 20 to 1500°C

A technique for measuring the absorption spectra of glasses and glass-forming melts in the red visible and near IR ranges, the experimental setup, and the measuring cell intended for use over a wide range of temperatures are described. The main problems concerning the acquisition of reliable data on the absorption spectra of glass-forming melts at high temperatures and the basic sources of errors in measurements of the spectra are considered.

Photostimulated electron transfer between coactivator ions in alkali silicate glasses

Silicate glasses of the composition (mol%) 22 R 2 O·3 CaO·75 SiO 2 (where R=Li, Na, K) have been studied. They were doped either with Ce 3+, or Tb 3+ ions, or with pairs (Ce 3+ + Fe 3+, Tb 3+ + Fe 3+, Tb 3+ + Eu 3+). The samples were melted in reducing (adding starch into the batch) or oxidizing (blowing oxygen through the glass liquid) conditions. Rare earth oxide concentration did not exceed 0.5 mol%, and that of Fe 2O 3 was varied from 0.004 to 0.025 mol% (the iron content in glasses without doping was at the level of 10 −4 wt%). The activators act as extrinsic (impurity) electron donors (D n +) and acceptors (A m +) in processes of their photooxidation (photoionization: Ce 3+, Tb 3+) and photoreduction (Fe 3+, Eu 3+) to form extrinsic (impurity) color centers (CCs), (D n +) + and (A m +) −. To create them, glasses were excited optically in the limits of UV absorption bands of a D n + (3.8 to 5.9 eV for Tb 3+, and 3.3 to 3.9 eV for Ce 3+). Spectral dependencies of the efficiency, η( E), of intrinsic electron CCs formation due to D n + photoionization were measured. While varying the energy, E e, of excitation quanta, two regions of η( E) were resolved for each donor. In each region, η( E e) was approximately invariant. Such spectral dependence is explained by the fact that the largest energy donor states are in the glasses' forbidden bands. Hence, an overbarrier mechanism and a tunneling mechanism are each activated with changing E e. There is a transition region for η between the two regions in which η decreases with decreasing E e and is caused by the inhomogeneous broadening of the donor energy levels. Decay curves of the donor phosphorescence, and photoinduced absorption spectra in glasses with D n + and with (D n + + A m +) at various mechanisms of the D n + ionization were studied and analyzed.

Spectroscopic behaviour of U(I) containing glasses

The aim of our research is to study materials that can have applications as lasers. For this reason, as preliminar work, we prepared in our laboratory some glasses whose composition is xPbO/yNa 2O/ zSiO 2, doped with U(VI) salts (Table I), to understand the PbO influence on the formation of the UO 2+ 2 moiety, especially because the U(VI) coordination in silicate and particular lead silicate glasses is not yet completely clarified [1]. Then we measured the absorption and emission spectra at different % mol SiO 2 PbO Na 2O U (1) 49.50 49.50 - 1.00 UO 2(OAc) 2 (2) 61.50 37.50 - 1.00 UO 2(OAc) 2 (3) 61.50 37.50 - 1.00 UO 3 (4) 61.50 37.50 - 1.00 Na 2UO 4 (5) 61.67 28.67 8.67 1.00 UO 2(NO 3) 2 (6) 61.67 24.67 12.67 1.00 UO 2(NO 3) 2 (7) 61.67 21.67 15.67 1.00 UO 2(NO 3) 2 (8) 61.67 19.67 17.67 1.00 UO 2(NO 3) 2 (9) 59.50 - 39.50 1.00 UO 2(OAc) 2 1 ass. (cm −1) fluor. (cm −1) (1) 19850 (2) 19850 (3) 19850 (4) 19850 (5) 20195, 24100 18740 (6) 20012, 24190 18080, 18740, 19395 (7) 20200, 24230 18080, 18740, 19395 (8) 20350(sh), 24200 18080, 18740, 19395 (9) 20548, 21692(sh), 23873 1 18080, 18740, 19395 1 The spectrum has been measured at 4.2 K. temperatures. Their maxima are reported in T able II. The analysis of the experimental data shows: 1. the absorption spectra of glasses with only PbO as network former are different from those containing also Na 2O, and only these show the presence of the UO 2+ 2 ion. 2. the intensity of the typical uranyl luminescence [2] using same thickness glasses, decreases with the increase of the PbO percentage and in the case of the lead silicate, the fluorescence completely disappears. Therefore, it is possible to deduce: a) the lack or a very low concentration of the UO 2+ 2 moiety in systems containing a high PbO percentage and b) the stabilization of the UO 2+ 2 ion in Na 2O rich systems, i.e. in strongly basic media (and this behaviour is very strange for Weyl [3] claimed the stabilization of U(VI) as UO 2+ 2 in acid glasses). A possible explanation of the above observations could be given on the basis of structural considerations. In fact, in the case of silicate glasses, the structure (no completely defined, indeed) is made by SiO 4 tetrahedra linked in a three-dimensional network. In Such a steric situation, it could be possible for the U(VI) ion to enter an interstitial site and form an UO 2+ 2 molecular ion. On the other hand, when we add PbO that enters as network former and network modifier, the system becomes much more distorted for the strong covalency of the PbO bond (obviously respect to the NaO bond) with consequent formation of bidimensional chains or (Si 2O 5) layers linked by Pb bridges [4]. This steric situation very probably is unfavourable to the formation of the UO 2+ 2 linear ion or to its presence in the interstices. As concluding remarks, we can say that the development of this research in which we tried to understand the spectroscopic and structural behaviour of hexavalent uranium in some lead and sodium silicate glasses in which the ratio Na 2O/PbO is changed, will be the preparation and the study of the systems xPbO/yNa 2O/zSiO 2/UO 2+ 2 /Ln 3+ because, as well known, the energy migration from UO 2+ 2 to Ln 3+ ions is very interesting and conceivably applicable to lasers.

Effect of composition and temperature on the absorption and emission spectra of molybdenum in glasses

Using suitable melting techniques, the lower oxidation states of molybdenum have been obtained in phosphate, borate and silicate glasses, and in the last two systems without the use of reducing agents. Absorption spectra of glasses containing very low concentrations of molybdenum show that the intensities of the bands depends on concentration so that extinction coefficients cannot be reported. The Mo (III) absorption bands in the borate glasses are at higher energies than in the phosphate but are not so readily analysed on the basis of ligand field theory. Both absorption and emission spectra in the phosphate glass have been measured at liquid helium temperatures and the results of some initial work on the ESR spectra are also reported.

Infrared absorption spectra in glasses on the basis of tetrahedral phases

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The distribution of transition elements in the system CaMgSi 2O 6Na 2Si 2O 5H 2O at 1,000 bars pressure

This study describes the results of experiments relating to the distribution of trace amounts of first row transition metal cations between diopside crystals and coexisting silicate liquid in a synthetic hydrothermal silicate system. The phase relations were determined for the system CaMgSi 2O 6Na 2Si 2O 5H 2O at 1,000 bars pressure. This system is characterized by a large field of diopside + liquid + vapour which extends to very sodium disilicate-rich portions of the system. An unknown incongruently melting phase is also present. The partition of the various transition elements between diopside crystals and coexisting silicate liquid was determined using an electron microprobe analyser. It was found that three elements, V, Cr and Ni became strongly enriched in the diopside crystals with decreasing temperature. Titanium exhibited a small tendency towards enrichment in the diopside with falling temperature. Cobalt was enriched in the diopside but was, nevertheless, rather insensitive to changes in temperature. With decreasing temperature from 1,070 to 925°C, this element displayed a slight tendency to leave the diopside, however, with temperatures decreasing from 925°C, there was a slight tendency towards increased enrichment in the diopside. All these results have been accounted for in terms of ligand field effects, bearing in mind the structural environment of the various transition metal ions in the silicate liquid as determined from absorption spectra of glasses. Thermodynamic data calculated from the experimental results further indicate the dominant importance of ligand field effects. Values obtained for ΔH° for exchange reactions involving the substitution of Mg in diopside by transition elements reflect the relative octahedral site preference energies for the transition metal cations. Values of ΔS° 1198 for the exchange reactions indicate that Cr 3+ was present essentially in one type of site in the silicate liquids (i.e., in octahedral sites) whereas Co 2+ and Ni 2+ were distributed over a number of different sites (i.e., both tetrahedral and octahedral sites). It was concluded that transition element distribution in a silicate system may be adequately predicted if details concerning its environment in the melt and the ligand field properties are known. It was noted that octahedral site preference energies should be used with caution in very high temperature portions of some silicate systems.