Novel selenium containing boro-phosphate glasses: preparation and structural study.

Science.gov (United States)

Ciceo-Lucacel, R; Radu, T; Ponta, O; Simon, V

2014-06-01

We synthesized a new boro-phosphate glass system with different %mol SeO2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P2O7(4-) dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO3(-) middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ3 or BØ2O(-) units. A small contribution of BØ4(-) units was also detected from the FT-IR spectra of glasses. For SeO2 content higher than 5mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. Copyright © 2014 Elsevier B.V. All rights reserved.

Influence of silver nanoparticles on the spectroscopic properties of Sm{sup 3+} doped boro-phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Suthanthirakumar, P.; Marimuthu, K., E-mail: emari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram - 624 302 (India)

2016-05-23

The Sm{sup 3+} doped novel boro-phosphate glasses containing silver nanoparticles (NPs) (SmBPxA) have been prepared following the melt quenching technique and their structural and spectroscopic behavior were studied through HR-TEM, optical absorption and photoluminescence spectral measurements. The TEM analysis validates the existence of Ag NPs with an average diameter of ~8 nm. The Surface plasmon resonance (SPR) band of silver NPs was found at around 600 nm from the absorption spectrum of the Sm{sup 3+} ions free glass sample. The optical band gap energy (E{sub opt}) corresponding to the direct and indirect allowed transitions and the Urbach energy (ΔE) values were determined from the absorption spectral measurements. The luminescence intensity is found to get enhance when the Ag NPs were embedded along with the Sm{sup 3+} ions in the prepared glasses due to the local electric field effect around the rare earth (RE) ion site produced by the SPR of Ag NPs.

Immobilization of gadolinium in iron borophosphate glasses and iron borophosphate based glass-ceramics: Implications for the immobilization of plutonium(Ⅲ)

Energy Technology Data Exchange (ETDEWEB)

Wang, Fu, E-mail: wangfu@swust.edu.cn; Liao, Qilong, E-mail: liaoqilong@swust.edu.cn; Dai, Yunya; Zhu, Hanzhen

2016-08-15

Immobilization of gadolinium (Gd), a nonradioactive surrogate for Pu{sup 3+}, in iron borophosphate glasses/glass-ceramics (IBP glasses/glass-ceramics) has been investigated. The IBP glass containing 4 mol% Gd{sub 2}O{sub 3} is homogeneously amorphous. At higher Gd{sub 2}O{sub 3} concentrations, additional Gd is retained in the glasses as crystalline inclusions of monazite GdPO{sub 4} crystalline phase detected with X-ray diffraction. Moreover, Gd{sub 2}O{sub 3} addition increases the T{sub g} of the IBP glasses in glass formation range, which is consistent with the structural modification of the glasses. The structure of the Gd{sub 2}O{sub 3}-loaded IBP glasses/glass-ceramics is mainly based on pyrophosphate units. The chemical durability of Gd{sub 2}O{sub 3}-loaded IBP glasses/glass-ceramics is comparable to widely used borosilicate glass waste forms and the existence of monazite GdPO{sub 4} crystalline phase does not degrade the aqueous chemical durability of the IBP glasses/glass-ceramics. The Gd-loading results imply that the solubility should not be a limiting factor in processing nuclide Pu{sup 3+} if the formed crystalline phase(s) have high chemical durability. - Highlights: • Monazite GdPO{sub 4} are identified in the IBP glasses containing up to 6 mol% Gd{sub 2}O{sub 3}. • R{sub L} of the Gd{sub 2}O{sub 3}-loaded IBP glasses/glass-ceramics are about 10{sup −2} g m{sup −2} d{sup −1}. • Existence of GdPO{sub 4} does not degrade aqueous chemical durability of the IBP glass. • T{sub g} increases with increasing Gd{sub 2}O{sub 3} content in glass formation range. • IBP glasses are potential hosts for the immobilization of Pu{sup 3+} containing HLWs.

A New Open-framework Iron Borophosphate from Ionic Liquids: KFe[BP2O8(OH

Directory of Open Access Journals (Sweden)

Guangmei Wang

2011-04-01

Full Text Available A new open-framework iron borophosphate, KFe[BP2O8(OH], has been obtained by ionothermal synthesis from KH2PO4, FeCl3∙4H2O, H3BO3 and [C4mpyr]Br (1-butyl-1-methylpyrrolidinium bromide. Single-crystal X-ray diffraction analysis shows that KFe[BP2O8(OH] (monoclinic, P21/c, a = 9.372(2 Å , b = 8.146(2Å , c = 9.587(2 Å, β = 101.18(3°, V = 718.0(2Å3 and Z = 4 has a three-dimensional (3-D framework structure composed by {Fe(IIIO5(OH} octahedra as well as {BO3(OH} and {PO4} tetrahedra. As anionic structural sub-unit, KFe[BP2O8(OH], contains an infinite open-branched {[BP2O8(OH]4-} chain which is formed by alternating {BO3(OH} and {PO4} tetrahedra. {Fe(IIIO5(OH} octahedra share common O corners with five phosphate tetrahedra and the OH corner links to the hydrogen borate group to give a 3D framework. The negative charges of the inorganic framework are balanced by K+ ions.

Luminescence studies on Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses for WLED applications

Science.gov (United States)

Vijayakumar, M.; Uma, V.; Arunkumar, S.; Marimuthu, K.

2015-06-01

Dy3+ and Dy3+:Eu3+ co-doped boro-phosphate glasses have been prepared and optically characterized using absorption, luminescence and decay measurements. The Nephelauxetic ratios (β), Bonding parameters (δ) and Judd-Ofelt (JO) intensity parameters Ωλ (λ = 2, 4 and 6) were calculated to study the nature of the environment around the RE3+ ions in the prepared glasses. The yellow to blue (Y/B) intensity ratio and the chromaticity color coordinates were calculated from the luminescence measurements. The lifetimes of the 4F9/2 excited level were measured using decay curves and is found to decrease in the Dy3+:Eu3+ co-doped glass due to the occurrence of resonant energy transfer between Dy3+-Eu3+ ions and the non-exponential decay rates have been fitted with Inokuti-Hirayama (IH) model. The decay curves are well fitted for S= 6 suggesting that the interaction between active ions for the energy transfer is of dipole-dipole nature.

Novel selenium containing boro-phosphate glasses: Preparation and structural study

Energy Technology Data Exchange (ETDEWEB)

Ciceo-Lucacel, R.; Radu, T., E-mail: teodora.radu@phys.ubbcluj.ro; Ponta, O.; Simon, V.

2014-06-01

We synthesized a new boro-phosphate glass system with different %mol SeO{sub 2} content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P{sub 2}O{sub 7}{sup 4−} dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO{sub 3}{sup −} middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ{sub 3} or BØ{sub 2}O{sup −} units. A small contribution of BØ{sub 4}{sup −} units was also detected from the FT-IR spectra of glasses. For SeO{sub 2} content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P{sub 2}O{sub 5}-CaO-B{sub 2}O{sub 3}-SeO{sub 2} glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system.

Novel selenium containing boro-phosphate glasses: Preparation and structural study

International Nuclear Information System (INIS)

Ciceo-Lucacel, R.; Radu, T.; Ponta, O.; Simon, V.

2014-01-01

We synthesized a new boro-phosphate glass system with different %mol SeO 2 content by conventional melt quenching technique. All samples were obtained in a glassy state with the vitreous structure confirmed by X-ray diffraction analysis. Scanning electron microscopy (SEM) revealed some non-homogeneous domains on the glasses surface, and their tendency to link each other once the selenium oxide content increases. Energy-dispersive X-ray analysis (EDAX) indicated similar elemental composition in different regions of each sample. X-ray photoelectron spectroscopy (XPS) was used to determine the nature of chemical bonding and the elemental composition at the sample surfaces, and Fourier transform infrared (FT-IR) spectroscopy was used to determine the structural groups in the obtained glass structure. Based on FT-IR results, the glass structure at short range order consists mainly of small phosphate units such as pyrophosphate (i.e. P 2 O 7 4− dimmers or terminating groups at the end of phosphate chains) and some metaphosphate (i.e. PO 3 − middle groups in the phosphate chains) units. The boron atoms are mainly placed in three-coordinated sites in BØ 3 or BØ 2 O − units. A small contribution of BØ 4 − units was also detected from the FT-IR spectra of glasses. For SeO 2 content higher than 5 mol%, the modifier role of selenium ions is strongly reflected on the local structure dominated in this case by pyrophosphate units. - Highlights: • New P 2 O 5 -CaO-B 2 O 3 -SeO 2 glasses synthesized by conventional melt quenching method. • Evidences for the Se ions modifier role in the local structure by FT-IR and XPS. • Significant advances in understanding the structural properties of the new system

Structural and luminescence properties of Mn2+ ions doped calcium zinc borophosphate glasses

International Nuclear Information System (INIS)

Wan, Ming Hua; Wong, Poh Sum; Hussin, Rosli; Lintang, Hendrik O.; Endud, Salasiah

2014-01-01

Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ( 4 T 1g → 6 A 1g ). • As the concentration of Mn 2+ ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn 2+ ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn 2+ ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper 4 T 1g → 6 A 1g ground state of Mn 2+ ions. As the concentration of Mn 2+ ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of 4 T 1g level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn 2+ concentrations. From the emission characteristic parameters of 6 A 1g (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices

Structural and luminescence properties of Mn{sup 2+} ions doped calcium zinc borophosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Wan, Ming Hua, E-mail: wanminghua819@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Wong, Poh Sum, E-mail: pohsumwong@gmail.com [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Hussin, Rosli, E-mail: roslihussin@utm.my [Phosphor Research Group, Department of Physics, Faculty of Science, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Lintang, Hendrik O., E-mail: hendrik@ibnusina.utm.my [Catalytic Science and Technology (CST) Research Group, Ibnu Sina Institute for Fundamental Science Studies, Universiti Teknologi Malaysia, Skudai 81310, Johor (Malaysia); Endud, Salasiah, E-mail: salasiah@kimia.fs.utm.my [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor Bahru, Johor (Malaysia)

2014-05-15

Highlights: • FT-IR revealed that the network structures are from borate and phosphate network. • The PL spectrum exhibits a green emission band at 582 nm ({sup 4}T{sub 1g} → {sup 6}A{sub 1g}). • As the concentration of Mn{sup 2+} ions is increased, the emission band had been red shifted. • These glasses are found to have potential applications as luminescent optical materials. - Abstract: Calcium zinc borophosphate glasses (CaZnBP) doped with various concentrations of Mn{sup 2+} ions and borate and phosphate as variable were prepared using conventional melt quenching technique. The structure of obtained glasses were examined by means of use: X-ray diffraction (XRD) and fourier transform infrared (FT-IR). XRD analysis confirmed amorphous nature of glass samples. The FT-IR spectra reveals the presence of both borate and phosphate vibrational modes in the prepared glasses. The doping of Mn{sup 2+} ions (2–10 mol%) shows no significant changes in the main IR vibrational bands. Optical properties were studied by measuring the near infrared photoluminescence (PL) spectra. CaZnBP glasses exhibited intense green emission peak (582 nm) (tetrahedral symmetry), which is assigned to a transition from the upper {sup 4}T{sub 1g} → {sup 6}A{sub 1g} ground state of Mn{sup 2+} ions. As the concentration of Mn{sup 2+} ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of {sup 4}T{sub 1g} level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn{sup 2+} concentrations. From the emission characteristic parameters of {sup 6}A{sub 1g} (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices.

[Mo5VMo7VIO30(BPO4)2(O3P-Ph)6]5-: a phenyl-substituted molybdenum(V/VI) boro-phosphate polyoxometalate.

Science.gov (United States)

Sassoye, Capucine; Norton, Kieran; Sevov, Slavi C

2003-03-10

The title polyanion is the first hybrid borophosphate-phenylphosphonate polyoxometalate. It was structurally characterized as its imidazolium salt, (C(3)N(2)H(5))(5)[Mo(12)O(30)(BPO(4))(2)(O(3)P-Ph)(6)].H(2)O (monoclinic, P2(1)/c, a = 22.120(3) A, b = 13.042(2) A, and c = 32.632(4) A, beta = 101.293(3) degrees ), which was synthesized hydrothermally from imidazole, molybdenum oxide and metal, and boric, phosphoric, and phenylphosphonic acids. The anion is the second example of a new class of polyoxometalates that resemble Dawson anions but where the two pole caps of three edge-sharing MoO(6) octahedra in the latter are replaced by other units, in this case tetrahedral borate sharing corners with three phenylphosphonic groups, [(OB)(O(3)P-Ph)(3)]. The 12 molybdenum atoms forming the two equatorial belts of the cluster are of mixed-valence, five are Mo(V) and seven are Mo(VI), and the resulting five electrons are delocalized. Four of these electrons are paired according to the temperature dependence of the magnetic susceptibility. The new compound is soluble in a mixture of water and pyridine (in equal volumes) as well as in nitromethane, and the anions are intact in these solutions.

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Transparent borophosphate glasses doped with CuO were prepared by melt quenching technique. X-ray diffraction (XRD), optical and luminescence properties of sodium–calcium borophosphate glasses doped with CuO have been studied. The XRD results showed the amorphous nature of the sample. The introduction of ...

Influence of alumina on photoluminescence and thermoluminescence characteristics of Gd{sup 3+} doped barium borophosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Kalpana, T. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Gandhi, Y. [Department of Physics, Kakani Venkata Ratnam College, Nandigama 521 185, A.P. (India); Sanyal, Bhaskar [Food Technology Division, Bhabha Atomic Research Center, Trombay, Mumbai 400 085 (India); Sudarsan, V. [Bhabha Atomic Research Centre, Chemistry Division, Mumbai 400 085 (India); Bragiel, P.; Piasecki, M. [Institute of Physics, Jan Dlugosz University, Ul. Armii Krajowej 13/15, Czestochowa 42-201 (Poland); Kumar, V. Ravi [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, A.P. (India)

2016-11-15

Gd{sup 3+} doped barium borophosphate glasses mixed with varying concentration of Al{sub 2}O{sub 3} are synthesized. Photoluminescence, thermoluminescence and other spectroscopic studies viz., IR and EPR spectral studies, have been carried out. IR spectral studies of these glasses indicated that there is a gradual increase in the degree of depolymerization of the glass network with increase in the concentration of Al{sub 2}O{sub 3} upto 3.0 mol%. The EPR spectral studies revealed the lowest concentration of Gd{sup 3+} ion clusters in the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3}. The photoluminescence emission spectra exhibited strong ultraviolet blue emission at 311 under excitation at 273 nm due to {sup 6}P{sub 7/2}→{sup 8}S{sub 7/2} transition of Gd{sup 3+} ions. The intensity of this band is found to be enhanced four times when the glass mixed with 3.0 mol% of Al{sub 2}O{sub 3} with respect to that of alumina free glass. The enrichment of this emission is attributed to the declustering of Gd{sup 3+} ions by Al{sup 3+} ions. Thermoluminescence (TL) characteristics of these glasses have also been investigated after irradiating them with different doses of γ-rays (in the range 0–8.0 kGy). The TL emission exhibited a dosimetric peak at about 200 °C. The TL output under this glow peak is observed to increase with increase of γ-ray dose. For any fixed γ-ray dose, the TL output is increased with increasing Al{sub 2}O{sub 3} content up to 3.0 mol% and beyond this concentration quenching of TL is observed. The mechanisms responsible for TL emission and the variation in TL output with the concentration of Al{sub 2}O{sub 3} are quantitatively discussed in terms of electron and hole centers developed due to interaction of γ-rays with the glass network. The dose response of these glass samples exhibited linear behavior in the dose range 0–8.0 kGy.

Study on the water durability of zinc boro-phosphate glasses doped with MgO, Fe2O3, and TiO2

Science.gov (United States)

Hwang, Moon Kyung; Ryu, Bong Ki

2016-07-01

The water durability of zinc boro-phosphate (PZB) glasses with the composition 60P2O5-20ZnO-20B2O3- xMeO ( x = 0, 2, 4, 6 and MeO = MgO, Fe2O3, or TiO2) (mol%) was measured, and PZB glass was studied in terms of its thermal properties, density, and FTIR characteristics. The surface conditions and corrosion byproducts were analyzed using scanning electron microscopy. When MgO, Fe2O3, and TiO2 were doped into the PZB glass, Q2 was decreased and Q1 was increased in the phosphate structure, while the number of BO4 structures increased with increasing MeO content. The density of the PZB glass was increased by the addition of Fe2O3 and TiO2, while the glass transition temperature ( T g ) and dilatometric softening temperature ( T d ) were increased when additional MgO, Fe2O3, and TiO2 were added. From the weight loss analysis (95 ◦ C, 96 h), TiO2 doped glass showed the lowest weight loss (1.70 × 10 -3 g/cm2) while MgO doped glass showed the highest value (2.44 × 10 -3 g/cm2), compared with PZB glass (3.07 × 10 -3 g/cm2). These results were discussed in terms of the Me n+ ions in the glass structure, and their different coordination numbers and bonding strengths.

Some features of borophosphatic catalysts structure with silicate bond

International Nuclear Information System (INIS)

Kubasov, A.A.; Kitaev, L.E.; Topchieva, K.V.; Gonchakova, N.N.

1979-01-01

The structure of borophosphatic catalysts is studied using the method of IR-spectroscopy. Silica gel and diatomite brick were used as a binding (carriers). To clarify the character of the carrier effect on borophosphate structure obtained were boric and phosphoric acid spectra, covered in the quantity of 10 weight % on SiO 2 , and also industrial catalyst H 3 PO 4 /SiO 2 of hydratation with higher P 2 O 5 content. At calcination of sample 10% H 3 BO 3 /SiO 2 in vacuum 932 cm -1 strip intensity increased with the temperature rise and that can be referred to B-O-Si vibrations. In the area of fundamental vibrations P-O and Si-O spectrum of the 10% H 3 PO 4 /SiO 2 sample, subjected to heating up to 600 deg C in the air, differed but slightly from the initial SiO 2 spectrum. In the spectrum of the sample with higher P 2 O 5 content after thermovapor treatment at 300 deg C in the frequency range of 500-800 cm -1 strips were detected, which testified to the phosphoric acid interaction with silica gel. The state of adsorbed water can be judged by the change of 1630 cm -1 strip optical density in the course of step thermovacuum borophosphate treatment. It was found that water was removed from the sample surface in the range of 200-300 deg C. Thus, at borophosphate catalysts calcination which contains SiO 2 , interaction took place between borophosphate and bind components accompanied by B-O-Si and P-O-Si bonds formation. Water removal from these catalyst surfaces took place at lower temperature as compared to individual borophosphate, which testified to certain release of electron acceptor properties as a result of the bind component introduction. Thus, the bind component introduction not only increases mechanical strength and hydrolytic stability of borophosphates but results in their surface modification

Corrosion resistance properties of enamels with high B2O3-P2O5 content to molten aluminum

International Nuclear Information System (INIS)

Zhou, M.; Li, K.; Shu, D.; Sun, B.D.; Wang, J.

2003-01-01

Anticorrosive properties of borophosphate and boron-free enamels to molten aluminum were investigated using SEM and electron probe. Carbonates of alkali metal and alkaline earth metal were added in an appropriate weight ratio to achieve desired melting temperature of the enamels. SEM examination on the solidified interface between the enamels and aluminum alloy show that the enamels can spread slightly on aluminum alloy. For anticorrosive sample of borophosphate enamel, phosphorus was not detected by electron probe at the side of aluminum alloy near the interface, but silicon was detected in the silica-free enamels side. For the sample of boron-free enamels, however, phosphorus was found at the side of aluminum alloy near the interface. It was revealed that the enamels with high B 2 O 3 -P 2 O 5 content have high corrosion resistance to molten aluminum

Bulletin of Materials Science | Indian Academy of Sciences

Indian Academy of Sciences (India)

Articles written in Bulletin of Materials Science. Volume ... Preparation and characterization of magnesium–aluminium–silicate glass ceramics ... Preparation and studies of some thermal, mechanical and optical properties of .... Surface degradation behaviour of sodium borophosphate glass in aqueous media: Some studies.

A study of the local structure around Eu3+ ions in oxide glasses using Moessbauer spectroscopy

International Nuclear Information System (INIS)

Todoroki, S.; Hirao, K.; Soga, N.

1993-01-01

The local structure around Eu 3+ ions in several oxide glasses (silicate, germanate and borophosphate glasses) was investigated by using 151 Eu Moessbauer spectroscopy. It was found that the isomer shift (IS) of silicate and borophosphate glasses was independent of the sodium content, but that of germanate glasses was not. This means the first coordination sphere around Eu 3+ ions in silicate glasses is insensitive to the composition of the glass matrix. It is assumed that, regardless of the sodium content, Eu 3+ ions in silicate glasses attract a certain amount of nonbridging oxygen (NBO, Si-O direct difference ) when incorporated stably into silicate glass matrix, because NBO is the only species donating negative charge. For germanate glasses, the behavior of IS is considered to be related to the resence of GeO 6/2 octahedra. On the basis of experimental results, the coordination models of Eu 3+ in these systems are proposed. (orig.)

Structure and properties of ZnO-B{sub 2}O{sub 3}-P{sub 2}O{sub 5}-TeO{sub 2} glasses

Energy Technology Data Exchange (ETDEWEB)

Mosner, Petr, E-mail: petr.mosner@upce.cz [Department of General and Inorganic Chemistry, University of Pardubice, Faculty of Chemical Technology, 53210 Pardubice (Czech Republic); Vosejpkova, Katerina; Koudelka, Ladislav [Department of General and Inorganic Chemistry, University of Pardubice, Faculty of Chemical Technology, 53210 Pardubice (Czech Republic); Montagne, Lionel; Revel, Bertrand [Unite de Catalyse et de Chimie du Solide - UCCS, Univ Lille Nord de France, F-59000, CNRS UMR 8181, USTL F-59655, ENSCL F-59652, Villeneuve d' Ascq (France)

2010-11-01

Zinc borophosphate glasses doped with TeO{sub 2} were studied in the compositional series (100 - x)[0.5ZnO-0.1B{sub 2}O{sub 3}-0.4P{sub 2}O{sub 5}]-xTeO{sub 2} in a broad concentration range of x = 0-80 mol% TeO{sub 2}. The structure of the glasses was studied by Raman and IR spectroscopy and by {sup 31}P and {sup 11}B MAS NMR spectroscopy. According to the Raman and IR spectra, TeO{sub 2} is incorporated in the structural network in the form of TeO{sub 3}, TeO{sub 3+1} and TeO{sub 4} structural units. The ratio of TeO{sub 4}/TeO{sub 3} increases with increasing TeO{sub 2} content in the glasses. The incorporation of TeO{sub x} units into the glass network is associated with the depolymerisation of phosphate chains, as revealed by Raman spectroscopy. The incorporation of TeO{sub 2} modifies also the coordination of boron atoms, where B(OP){sub 4} structural units are gradually replaced by B(OP){sub 4-n}(OTe){sub n} units. The addition of TeO{sub 2} to the parent zinc borophosphate glass results in a decrease of glass transition temperature associated with the replacement of stronger P-O and B-O bonds by weaker Te-O bonds. Chemical durability of glasses reveals a minimum at the glass containing 10 mol% TeO{sub 2}, but with further additions of TeO{sub 2} it improves and the glasses with a high TeO{sub 2} content reveal better durability than the parent zinc borophosphate glass.

Sol-gel processing of glasses and glass-ceramics for microelectronic packaging

International Nuclear Information System (INIS)

Sriram, M.A.; Kumta, P.N.

1992-01-01

In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speeds calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency. Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glass-ceramic materials have been identified over the years which show good promise as candidate substrate materials. among these borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant. This paper reports that sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, Differential thermal analyses and FTIR have been used to characterize the as-prepared and heat treated gels

Viscosity properties of sodium borophosphate glasses

International Nuclear Information System (INIS)

Gaylord, S.; Tincher, B.; Petit, L.; Richardson, K.

2009-01-01

The viscosity behavior of (1 - x)NaPO 3 -xNa 2 B 4 O 7 glasses (x = 0.05-0.20) have been measured as a function of temperature using beam-bending and parallel-plate viscometry. The viscosity was found to shift to higher temperatures with increasing sodium borate content. The kinetic fragility parameter, m, estimated from the viscosity curve, decreases from 52 to 33 when x increases from 0.05 to 0.20 indicating that the glass network transforms from fragile to strong with the addition of Na 2 B 4 O 7 . The decrease in fragility with increasing x is due to the progressive depolymerization of the phosphate network by the preferred four-coordinated boron atoms present in the low alkali borate glasses. As confirmed by Raman spectroscopy increasing alkali borate leads to enhanced B-O-P linkages realized with the accompanying transition from solely four-coordinated boron (in BO 4 units) to mixed BO 4 /BO 3 structures. The glass viscosity characteristics of the investigated glasses were compared to those of P-SF67 and N-FK5 commercial glasses from SCHOTT. We showed that the dependence of the viscosity of P-SF67 was similar to the investigated glasses due to similar phosphate network organization confirmed by Raman spectroscopy, whereas N-FK5 exhibited a very different viscosity curve and fragility parameter due to its highly coordinated silicate network

Vitrification of high-level alumina nuclear waste

International Nuclear Information System (INIS)

Brotzman, J.R.

1979-01-01

Borophosphate glass compositions have been developed for the vitrification of a high-alumina calcined defense waste. The effect of substituting SiO 2 , P 2 O 5 and CuO for B 2 O 3 on the viscosity and leach resistance was measured. The effect of the alkali to borate ratio and the Li 2 O:Na 2 O ratio on the melt viscosity and leach resistance was also measured

Lithium manganese(II) diaqua-boro-phosphate monohydrate.

Science.gov (United States)

Zhuang, Rong-Chuan; Chen, Xue-Yun; Mi, Jin-Xiao

2008-07-05

The title compound, LiMn(H(2)O)(2)[BP(2)O(8)]·H(2)O, is built up of an open framework of helical borophosphate ribbons inter-connected by MnO(4)(H(2)O)(2) octa-hedra, forming one-dimensional channels along [001] occupied by Li(+) cations and disordered H(2)O mol-ecules (site occupancy 0.5). The Li cations reside in two partially occupied sites [occupancies = 0.42 (3) and 0.289 (13)] near the helices.

Existence of the uranyl ion at regular Sr site in U doped SrBPO5

International Nuclear Information System (INIS)

Mithlesh Kumar; Mohapatra, M.; Natarajan, V.

2014-01-01

Actinide doped alkaline earth borophosphates of the general formula MBPO 5 (M = Ca 2+ , Sr 2+ , Ba 2+ ) are of special interest due to array of defect centers that can be generated in these compounds by internal (α and γ) irradiation effects. Further, the crystalline alkaline earth borophosphates are also reported to be isostructural with stillwellite-LnBSiO 5 , which are built up by BO 4 and SiO 4 tetrahedra. This structure suggests that the host MBPO 5 should be a good matrix for luminescence investigations for suitable activator ions. The important advantages of MBPO 5 type systems are their high luminescence, moderate preparation temperature and low thermal degradation. XRD pattern of the prepared phosphor confirmed the formation of SrBPO 5 in a single phase. The presence of uranium in SrBPO 5 sample was ascertained from Energy Dispersive X-ray Fluorescence (EDXRF) measurements performed on a Jordan Valley instrument. The U content in the sample was found to be about 0.85%. An Inductively Coupled Plasma Atomic Emission Spectrometric (ICP-AES), Jobin Yvon, France was used for analysis of the sample, which showed all other metallic impurities except U to be present at concentrations below 5 :U, PL, TSL and ESR studies were conducted on the solid state route samples. PL and TSL techniques were used with a view to understand the species responsible for the luminescence and its site symmetry

Spectral studies on CuO in sodium–calcium borophosphate glasses

Indian Academy of Sciences (India)

linear optical devices [10] and as low-melting glass solders or glass seals [11] derived .... For S1 to S4 samples, the vitreous phase coexists with a crystalline phase and the pattern shows large maxima overlapped with the peaks characteristics ...

Zero photoelastic and water durable ZnO-SnO-P2O5-B2O3 glasses

Science.gov (United States)

Saitoh, Akira; Nakata, Kohei; Tricot, Grégory; Chen, Yuanyuan; Yamamoto, Naoki; Takebe, Hiromichi

2015-04-01

We report properties of zero birefringent xZnO-(67-x)SnO-(33-y)P2O5-y B2O3 glasses, within 18.5 ≤ x ≤ 22 and y = 0, 3, and 10 mol. %. These compositions of boro-phosphate glasses provide both zero photoelastic constant (PEC) and improved water durability. x = 19 and y = 3 compositions show minimum PEC of -0.002 × 10-12 Pa-1, which can contribute to candidate material for fiber current sensor devise without lead. The structures of zero photoelastic glasses were investigated by Raman scattering and nuclear magnetic resonance spectroscopies. Compositions of zero PEC glasses are explained by the empirical model proposed by Zwanziger et al. [Chem. Mater. 19, 286-290 (2007)].

New polyanion-based cathode materials for alkali-ion batteries

Science.gov (United States)

Yaghoobnejad Asl, Hooman

A number of new materials have been discovered through exploratory synthesis with the aim to be studied as the positive electrode (cathode) in Li-ion and Na-ion batteries. The focus has been set on the ease of synthesis, cost and availability of active ingredients in the battery, and decent cycle-life performance through a combination of iron and several polyanionic ligands. An emphasis has been placed also on phosphite (HPO32-) as a polyanionic ligand, mainly due to the fact that it has not been studied seriously before as a polyanion for cathode materials. The concept of mixed polyanions, for example, boro-phosphate and phosphate-nitrates were also explored. In each case the material was first made and purified via different synthetic strategies, and the crystal structure, which dominantly controls the performance of the materials, has been extensively studied through Single-Crystal X-ray Diffraction (SCXRD) or synchrotron-based Powder X-ray Diffraction (PXRD). This investigation yielded four new compositions, namely Li3Fe 2(HPO3)3Cl, LiFe(HPO3)2, Li0.8Fe(H2O)2B[P2O8]•H 2O and AFePO4NO3 (A = NH4/Li, K). Furthermore, for each material the electrochemical performance for insertion of Li+ ion has been studied by means of various electrochemical techniques to reveal the nature of alkali ion insertion. In addition Na-ion intercalation has been studied for boro-phosphate and AFePO4NO3. Additionally a novel synthesis procedure has been reported for tavorite LiFePO4F 1-x(OH)x, where 0 ≤ x ≤ 1, an important class of cathode materials. The results obtained clearly demonstrate the importance of crystal structure on the cathode performance through structural and compositional effects. Moreover these findings may contribute to the energy storage community by providing insight into the solid-state science of electrode material synthesis and proposing new alternative compositions based on sustainable materials.

Zero photoelastic and water durable ZnO–SnO–P2O5–B2O3 glasses

Directory of Open Access Journals (Sweden)

Akira Saitoh

2015-04-01

Full Text Available We report properties of zero birefringent xZnO–(67–xSnO–(33–yP2O5–y B2O3 glasses, within 18.5 ≤ x ≤ 22 and y = 0, 3, and 10 mol. %. These compositions of boro-phosphate glasses provide both zero photoelastic constant (PEC and improved water durability. x = 19 and y = 3 compositions show minimum PEC of −0.002 × 10−12 Pa−1, which can contribute to candidate material for fiber current sensor devise without lead. The structures of zero photoelastic glasses were investigated by Raman scattering and nuclear magnetic resonance spectroscopies. Compositions of zero PEC glasses are explained by the empirical model proposed by Zwanziger et al. [Chem. Mater. 19, 286-290 (2007].

Zero photoelastic and water durable ZnO–SnO–P{sub 2}O{sub 5}–B{sub 2}O{sub 3} glasses

Energy Technology Data Exchange (ETDEWEB)

Saitoh, Akira; Nakata, Kohei; Yamamoto, Naoki; Takebe, Hiromichi [Graduate School of Science and Engineering, Ehime University, 3 Bunkyo-cho, Matsuyama 790-8577 (Japan); Tricot, Grégory; Chen, Yuanyuan [LASIR UMR-CNRS 8516, Université de Lille 1, Villeneuve d’Ascq F-59655 (France)

2015-04-01

We report properties of zero birefringent xZnO–(67–x)SnO–(33–y)P{sub 2}O{sub 5}–y B{sub 2}O{sub 3} glasses, within 18.5 ≤ x ≤ 22 and y = 0, 3, and 10 mol. %. These compositions of boro-phosphate glasses provide both zero photoelastic constant (PEC) and improved water durability. x = 19 and y = 3 compositions show minimum PEC of −0.002 × 10{sup −12} Pa{sup −1}, which can contribute to candidate material for fiber current sensor devise without lead. The structures of zero photoelastic glasses were investigated by Raman scattering and nuclear magnetic resonance spectroscopies. Compositions of zero PEC glasses are explained by the empirical model proposed by Zwanziger et al. [Chem. Mater. 19, 286-290 (2007)].

Structure and properties of MoO.sub.3./sub.-containing zinc borophosphate glasses

Czech Academy of Sciences Publication Activity Database

Šubčík, J.; Koudelka, L.; Mošner, P.; Montagne, L.; Revel, B.; Gregora, Ivan

2009-01-01

Roč. 355, 16-17 (2009), 970-975 ISSN 0022-3093 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : glass formation * glass es * phosphates * structure Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.252, year: 2009

Acid-base synergistic flame retardant wood pulp paper with high thermal stability.

Science.gov (United States)

Wang, Ning; Liu, Yuansen; Xu, Changan; Liu, Yuan; Wang, Qi

2017-12-15

Acid-catalytic degradation caused by acid source flame retardants is the main reason for a decline in thermal stability of flame-retarded lignocellulosic materials. In the present research, a guanidine phosphate (GP)/borax (BX) flame retardant system based on acid-base synergistic interaction was designed and used in wood pulp paper (WPP) to solve this problem. Results showed that the treated WPP obtained good flame retardancy with a limiting oxygen index (LOI) value of 35.7%. As a basic flame retardant, borax could chemically combine with the acids released by guanidine phosphate, thus decreasing the acidity of the system in the initial heating stage. In this way, acid-catalytic degradation is greatly retarded on the lignocelluloses to improve thermal stability (the temperature of maximum degradation peak from 286°C to 314°C). Meanwhile, borax was also advantageous to form a denser and firmer condensed phase through reinforcement of the acid-base reaction product, borophosphates, allowing it to provide a protective barrier with higher quality. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correlation Between Electrical Conductivity and Catalytic Property in 78V{sub 2}O{sub 5}–15P{sub 2}O{sub 5}–7B{sub 2}O{sub 3} Glass Containing Fe{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Jeong, Hwa-Jin; Kim, Jong-hwan; Ryu, Bong-Ki [Pusan National University, Busan (Korea, Republic of)

2016-12-15

In this study, we established a correlation between the electrical conductivity and catalytic properties of vanadium borophosphate glass containing Fe{sub 2}O{sub 3}. Glasses were synthesized in the 78V{sub 2}O{sub 5}–15P{sub 2}O{sub 5}–7B{sub 2}O{sub 3} ternary-system containing x mol% Fe{sub 2}O{sub 3} (x = 1, 5, 7.5, and 10). Electrical conductivity was measured at 45 ℃ for samples heat-treated at 340 ℃ for 12 h. To examine catalytic effects, we used TGA measurements of a mixture of fatty acid and sample powders. Fourier transform infrared spectroscopy (FTIR) was used to analyze the structural changes after crystallization, while X-ray photoelectron spectroscopy (XPS) analysis indicated changes with different valence state ions. X-ray diffraction (XRD) analysis of the structure array verified these inferred changes. Conductivity and catalytic effects are discussed in relation to the migration of vanadate ions and iron ions with different valence states due to the increase crystallinity.

Structure and properties of barium tin boro-phosphate glass systems with very low photoelastic constant

Science.gov (United States)

Itadani, M.; Tricot, G.; Doumert, B.; Takebe, H.; Saitoh, A.

2017-08-01

Glasses in the BaO-SnO-P2O5-B2O3 system were prepared and evaluated in order to formulate preform glasses suitable for the fabrication of fiber cores with a very low photoelastic constant. A first glass system (I: xBaO-(60-x)SnO-40P2O5) was designed with a constant P2O5 content and various BaO contents (0-40 mol. %). Introduction of 3 mol. % of B2O3 to enhance the glass stability leads to the second glass system (II: x'BaO-(57-x')SnO-40P2O5-3B2O3) with 33-38 mol. % BaO. The structure of both systems was investigated by 1D/2D magic-angle spinning nuclear magnetic resonance, Raman, and Fourier transform infrared spectroscopic techniques. 31P NMR showed the presence of Q2 and Q1 units in the first system and correlation 11B/31P NMR indicated that boron enters into the network as B(OP)4 structural units. The photoelastic constant was determined and the stability of the best formulations as well as their refractive index dispersion was established. The drawing temperature and isothermal heating time (without crystal precipitation) parameters were also accurately measured by using experimental time-temperature-transition. Considering that the refractive indices of the core and the cladding materials must match, detailed core and cladding compositions for a fiber enabling single-mode waveguide transmission were proposed.

Flame retardancy mechanisms of bisphenol A bis(diphenyl phosphate) in combination with zinc borate in bisphenol A polycarbonate/acrylonitrile-butadiene-styrene blends

International Nuclear Information System (INIS)

Pawlowski, Kristin H.; Schartel, Bernhard; Fichera, Mario A.; Jaeger, Christian

2010-01-01

Bisphenol A polycarbonate/acrylonitrile-butadiene-styrene (PC/ABS) with and without bisphenol A bis(diphenyl phosphate) (BDP) and 5 wt.% zinc borate (Znb) were investigated. The pyrolysis was studied by thermogravimetry (TG), TG-FTIR and NMR, the fire behaviour with a cone calorimeter applying different heat fluxes, LOI and UL 94. Fire residues were examined with NMR. BDP affects the decomposition of PC/ABS and acts as a flame retardant in the gas and condensed phases. The addition of Znb results in an additional hydrolysis of PC. The fire behaviour is similar to PC/ABS, aside from a slightly increased LOI and a reduced peak heat release rate, both caused by borates improving the barrier properties of the char. In PC/ABS + BDP + Znb, the addition of Znb yields a borate network and amorphous phosphates. Znb also reacts with BDP to form alpha-zinc phosphate and borophosphates that suppress the original flame retardancy mechanisms of BDP. The inorganic-organic residue formed provides more effective flame retardancy, in particular at low irradiation in the cone calorimeter, and a clear synergy in LOI, whereas for more developed fires BDP + Znb become less effective than BDP in PC/ABS with respect to the total heat evolved.

Reuse of hazardous calcium fluoride sludge from the integrated circuit industry.

Science.gov (United States)

Zhu, Ping; Cao, Zhenbang; Ye, YiLi; Qian, Guangren; Lu, Bo; Zhou, Ming; Zhou, Jin

2013-11-01

The Chinese integrated circuit industry has been transformed from a small state-owned sector into a global competitor, but chip manufacturing produces large amounts of calcium fluoride sludges (CFS). In China, landfill is a current option for treating CFS. In order to solve the problem of unavailable landfill sites and prevent fluorine from dissolved CFS polluting water sources, CFS was tested as a component for a ceramic product made with sodium borate, sodium phosphate and waste alumina using a low-temperature sintering technology, and the effects of various factors on characteristics of the ceramic were investigated to optimize the process. The best sintering temperature was controlled at 700°C, and the optimal raw material ratio of the ceramic was 11% sodium borate, 54% sodium phosphate, 30% CFS and 5% waste alumina. The CFS ceramic was characterized by a morphological structure and X-ray diffraction. The results indicated that CFS was transformed into Na2Ca(PO4)F as an inert and a main crystalline phase in the ceramic, which was enclosed by the borophosphate glass. Toxicity characteristic leaching procedure, corrosion resistance and compressive strength tests verified CFS ceramic as a qualified construction ceramic material, and the fluorine from CFS was solidified in the inert crystalline phase, which would not be released to cause secondary pollution. This novel technology not only avoids the CFS hydrolyzing reaction forming harmful hydrofluoric acid gas at 800°C and above, but also produces high-performance ceramics as a construction material, in accordance with the concept of sustainable development.

Lithium-Ion Mobility in Quaternary Boro-Germano-Phosphate Glasses.

Science.gov (United States)

Moguš-Milanković, Andrea; Sklepić, Kristina; Mošner, Petr; Koudelka, Ladislav; Kalenda, Petr

2016-04-28

Effect of the structural changes, electrical conductivity, and dielectric properties on the addition of a third glass-former, GeO2, to the borophosphate glasses, 40Li2O-10B2O3-(50 - x)P2O5-xGeO2, x = 0-25 mol %, has been studied. Introduction of GeO2 causes the structural modifications in the glass network, which results in a continuous increase in electrical conductivity. Glasses with low GeO2 content, up to 10 mol %, show a rapid increase in dc conductivity as a result of the interlinkage of slightly depolymerized phosphate chains and negatively charged [GeO4](-) units, which enhances the migration of Li(+) ions. The Li(+) ions compensate these delocalized charges connecting both phosphate and germanium units, which results in reduction of both bond effectiveness and binding energy of Li(+) ions and therefore enables their hop to the next charge-compensating site. For higher GeO2 content, the dc conductivity increases slightly, tending to approach a maximum in Li(+) ion mobility caused by the incorporation of GeO2 units into phosphate network combined with conversion of GeO4 to GeO6 units. The strong cross-linkage of germanium and phosphate units creates heteroatomic P-O-Ge bonds responsible for more effectively trapped Li(+) ions. A close correspondence between dielectric and conductivity parameters at high frequencies indicates that the increase in conductivity indeed is controlled by the modification of structure as a function of GeO2 addition.

Effect of B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution on the properties and structure of tin boro-phosphate glasses

Energy Technology Data Exchange (ETDEWEB)

Saitoh, Akira, E-mail: asaito@ehime-u.ac.jp [Graduate School of Science and Engineering, Ehime University, Matsuyama, 3 Bunkyo-cho (Japan); Tricot, Grégory [LASIR UMR-CNRS 8516, Université de Lille 1, Villeneuve d' Ascq 59655 (France); UCCS UMR-CNRS 8181, Université de Lille 1, Villeneuve d' Ascq 59655 (France); Rajbhandari, Prashant [UCCS UMR-CNRS 8181, Université de Lille 1, Villeneuve d' Ascq 59655 (France); Anan, Shoji; Takebe, Hiromichi [Graduate School of Science and Engineering, Ehime University, Matsuyama, 3 Bunkyo-cho (Japan)

2015-01-15

Effect of B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution on the properties and structure of the ternary 67SnO–(33–x)P{sub 2}O{sub 5}–xB{sub 2}O{sub 3} composition line (from x = 0–33 mol%) are examined in this contribution. We show that density and glass transition temperature increase while molar volume and thermal expansion coefficient decrease with increasing B{sub 2}O{sub 3} concentration. Density and thermal properties experience an original three-domain evolution with rapid (region I: 0 ≤ x < 5), substantial (II: 5 < x ≤ 15), and moderate (III: 15 < x ≤ 33) increase. In order to explain this unconventional behaviour, the glass structure has been investigated using high magnetic field 1 dimensional {sup 31}P and {sup 11}B MAS–NMR, micro-Raman and infrared spectroscopies. {sup 11}B MAS–NMR experiments allow to (i) monitor the 3- and 4-fold coordinated borate species proportion and (ii) highlight the presence of unreported 4-fold coordinated species in the region (III). Finally, it is shown that substitution of P{sub 2}O{sub 5} by B{sub 2}O{sub 3} induces an alteration of the dimeric phosphate network and formation of mixed anion structure that consists of Q{sup 0} phosphate units, 3- and 4-fold coordinated borate units and their combinations. - Highlights: • We examined B{sub 2}O{sub 3}/P{sub 2}O{sub 5} substitution effect on the ternary SnO–P{sub 2}O{sub 5}–B{sub 2}O{sub 3} glasses. • We show a three-domains evolution for density and thermal properties. • The structure was investigated by {sup 31}P and {sup 11}B NMR, Raman and IR spectroscopies. • 3 and 4-folded borate species and unreported 4-folded species are revealed. • Mixed anion structure consists of Q{sup 0} phosphate unit and 3- and 4-folded borate units.

Optical properties of Eu3+ & Tb3+ ions doped alkali oxide (Li2O/ Na2O/ K2O) modified boro phosphate glasses for red, green lasers and display device applications

Science.gov (United States)

Moulika, G.; Sailaja, S.; Reddy, B. Naveen Kumar; Reddy, V. Sahadeva; Dhoble, S. J.; Reddy, B. Sudhakar

2018-04-01

In this article we report on alkali oxide modified borophosphate glasses doped with Eu3+and Tb3+ ions, with the chemical composition of 69.5 B2O3+10P2O5 + 10CaF2 + 5 Li2O+ 5ZnO+ R+ 0.5 Eu2O3 [where R = 5 (LiO2/Na2O/K2O)] have been prepared by conventional melt quenching technique, and the spectroscopic properties of the prepared glasses have been studied by XRD, Optical absorption, excitation and emission spectral analysis. XRD spectrum of the glasses have shown the amorphous nature of the glasses. The red emission corresponding to 5D0 → 7F2 (613 nm) transition was observed under the excitation of 394 nm wavelength, corresponding to Eu3+ ions, for all the prepared glasses. For Eu3+ ion doped glasses, emission bands were observed, such as; 5D1→ 7F1 (538 nm), 5D0→ 7F0 (580 nm), 5D0→ 7F1 (592 nm), 5D0→ 7F2 (613 nm), 5D0→ 7F3 (613 nm) and 5D0→ 7F4 (702 nm) are identified. In the case of Tb3+ ion doped glasses, four emission lines were observed, such as 5D4→ (7F6, 7F5, 7F4), which are located at 489 nm, 545 nm and 585 nm, respectively, after the samples were excited with 376 nm ultraviolet source. The green emission corresponding to 5D4 → 7F5 (543 nm) transition was observed under excitation wavelength 376 nm of the Tb3+ ions for all the prepared glasses. For all these emission bands, the decay curves were recorded to evaluate the emission life times. The mechanism underlying the observed emission from the glasses was explained in terms of energy levels.

Organic Minerals in the Origin of Life

Science.gov (United States)

Benner, S.; Biondi, E.; Kim, H. J.

2017-12-01

Models for the origin of life are plagued by fundamental problems that, due to their difficulty, are called "paradoxes". One of these, known to anyone who has ever worked in a kitchen, is that organics, when given energy and left to itself, does not generate life. Rather, organics devolve to give tarry mixtures that become increasingly complex and increasingly less likely to support life (like asphalt). However, even if those mixtures escape devolution to create something useful for Darwinism, like building blocks for RNA, the water in which they must work is corrosive, leading to their destruction. Even if RNA is created, it is itself easily degraded. One current trend to manage those paradoxes turns to minerals in environments on early Earth. Inorganic minerals containing borate have now been shown to prevent the destruction of ribose (the R in RNA) and other carbohydrates essential for early Earth. Evaporite desert basins supplied with aqueous runoff from tourmaline-containing basalts are ideal environments for forming borate minerals, especially if they are made alkaline by serpentinizing peridotite. In the evaporite environments, drying cycles mitigate the destructive capability of water. Further, we have shown that phosphate is segregated from calcium (avoiding formation of relatively unreacted apatites) if magnesium and borate are present. Further, a common magnesium borophosphate (luneburgite) not only makes phosphate available for prebiotic synthesis, but selectively phosphorylates RNA building blocks as it releases borate to stabilize them against further degradation. Finally, a variety of minerals bind and stabilize RNA itself. Research in this area has also discovered organic minerals that might have been relevant to the origins of life on Earth. Such minerals are scarce on Earth today, since they are easily consumed by microbial communities. However, on a prebiotic Earth, organic minerals could have stored organic species as intermediates towards our

A new series of borophosphate phosphor Cd{sub 3}BPO{sub 7}:M (M = Ce{sup 3+}, Tb{sup 3+}, Mn{sup 2+}) with tunable luminescence and energy transfer properties

Energy Technology Data Exchange (ETDEWEB)

Cao, Xiyu; Liu, Wei, E-mail: weiliu@ouc.edu.cn; Liu, Shuang; Cao, Lixin; Su, Ge; Gao, Rongjie; Jiang, Yu

2016-04-25

A new series of Cd{sub 3}BPO{sub 7}:M (M = Ce{sup 3+}, Tb{sup 3+}, Mn{sup 2+}) phosphors have been synthesized and characterized using X-ray powder diffraction as well as excitation and emission spectroscopy. Based on the Cd{sub 3}BPO{sub 7} host, the singly doping Ce{sup 3+}, Tb{sup 3+} and Mn{sup 2+} yield the blue, green and red-emitting phosphors respectively under the irradiation range from 270 to 300 nm UV. By appropriate tuning of Tb{sup 3+} or Mn{sup 2+} activator content, the emission color of the Cd{sub 3}BPO{sub 7}:Ce{sup 3+}/M (M = Tb{sup 3+} or Mn{sup 2+}) phosphors can be changed from blue to green or pink, respectively. Under UV excitation, the mixture of the as-prepared blue, green and red phosphors yields the warm white light, which exhibits their potential application as UV-convertible phosphors for WLEDs. - Highlights: • A new series of Cd{sub 3}BPO{sub 7}:M (M = Ce{sup 3+}, Tb{sup 3+}, Mn{sup 2+}) phosphors have been prepared. • The energy transfer from Ce{sup 3+} to Tb{sup 3+} is observed in Cd{sub 3}BPO{sub 7}:Ce{sup 3+}, Tb{sup 3+}. • Warm white light can be achieved by mixing physically the obtained tirphosphors.

Fixation of Simulated Highly Radioactive Wastes in Glassy Solids; Fixation de Dechets Simules de Haute Activite dans des Soudes Vitreux; 0424 0418 041a 0421 0410 0426 0418 042f 0418 041c 0418 0422 0418 0420 041e 0412 0410 041d 041d 042b 0425 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 041e 0422 0425 041e 0414 041e 0412 0412 042b 0421 041e 041a 041e 0419 0410 041a 0422 0418 0412 041d 041e 0421 0422 0418 0421 0422 0415 041a 041b 041e 041e 0411 0420 0410 0417 041d 042b 041c 0418 0422 0412 0415 0420 0414 042b 041c 0418 0412 0415 0429 0415 0421 0422 0412 0410 041c 0418 ; Fijacion de Desechos Simulados de Elevada Radiactividad en Solidos Vitreos

Energy Technology Data Exchange (ETDEWEB)

Clark, W. E.; Godbee, H. W. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1963-02-15

Current laboratory development work at ORNL aims at incorporating high-activity-level wastes in high-density insoluble glasses, containing all radioactive constituents in the solid. Experiments with simulated TBP-25 (aluminium, HNOs), Purex and Darex (stainless steel, HNOs) wastes have indicated the technical feasibility of such a process. Dense, microcrystalline solids may be as acceptable as true glasses; their greater thermal conductivity compensates somewhat for the increase in surface area over that of true glasses. Phosphate and borophosphate glasses were prepared from all three types of waste in thelaboratory.Caesium volatility was limited to the - 0.1% due to physical entrainment, and ruthenium volatility was lowered to -0.5% by addition of phosphite or hypophosphite. Other additives included PbO, Ca(OH){sub 2}, NaOH, and MgO. Bulk densities varied from 2.36 to 2.90 g/cm{sup 3} for TBP-25 and from 2.63 to 2.80 g/cm{sup 3} for Purex waste. Corresponding volume reductions from the concentrated waste solutions were 7.2 -9.3 and 5.7 - 8.3; initial softening points varied from 875 to 100 Degree-Sign C and from 830 to 975 Degree-Sign C respectively. Darex tests are still preliminary. Semi-continuous operation on a semi-engineering scale produced a true glass from TBP-25 waste and a microcrystalline solid from Purex. The thermal conductivity of the glass varied from 1.05 BTU/hr-ft-F Degree-Sign at 320 Degree-Sign F to 1.6 at 1050 Degree-Sign F, about 10 times higher than that of the calcine without additives. Ruthenium volatility was held to <10% by phosphite addition. Stainless steel is a satisfactory material for construction of the calcination-fixation container. Essentially all the internal corrosion takes place during the relatively short (2-6 hr) period in which the last of the acid and water are expelled at the maximum temperature. Melt production increased the corrosion of 304L stainless steel from 5 to 42 mil/month for a 24-hr evaporation-fixation cycle