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Sample records for borophosphates

  1. FROTTEMENT INTERNE DES VERRES DE BOROPHOSPHATES ALCALINS

    OpenAIRE

    Phalippou, J.; Woignier, T.; Zarzycki, J.

    1983-01-01

    L'étude du frottement interne des verres de borates et de borophosphates alcalins a permis de mettre en évidence l'influence de P2O5 sur l'apparition d'un second pic de relaxation. Son intensité dépend de la teneur initiale en eau du matériau, mais elle est aussi fortement augmentée lorsque le verre est soumis à une attaque par la vapeur d'eau. Deux hypothèses peuvent être émises pour rendre compte de ces phénomènes.

  2. WO.sub.3./sub.-doped zinc borophosphate glasses

    Czech Academy of Sciences Publication Activity Database

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

    2009-01-01

    Roč. 50, č. 4 (2009), 243-248. ISSN 1753-3562 R&D Projects: GA AV ČR KAN301370701 Institutional research plan: CEZ:AV0Z10100520 Keywords : tungstate zinc borophosphate glasses * Raman spectroscopy * temperature * NMR Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.553, year: 2009

  3. Nonlinear electronic polarization and optical response in borophosphate BPO4

    Science.gov (United States)

    Li, Zhi; Liu, Qiong; Han, Shujuan; Iitaka, Toshiaki; Su, Haibin; Tohyama, Takami; Jiang, Huaidong; Dong, Yongjun; Yang, Bin; Zhang, Fangfang; Yang, Zhihua; Pan, Shilie

    2016-06-01

    The electronic structure, nonlinear electronic polarization induced by a static external electric field, and frequency dependent second-harmonic susceptibility tensor of the borophosphate BPO4 are studied by a first-principles calculation based on density-functional theory. Our calculated results show that the borophosphate BPO4 has a large band gap ˜10.4 eV, which is larger than the band gap of the widely used nonlinear optical crystal KBe2BO3F2 . However, BPO4 also has a nonlinear coefficient d36=0.92 pm/V at static limit, which also is larger than the nonlinear coefficient d11=0.47 pm/V of KBe2BO3F2 . The unexpected larger nonlinear coefficient of BPO4 can be interpreted by the relatively strong s -p hybridization in BPO4, which can enhance the inter-band Berry connections, while the O 2 p orbitals dominating valence bands in KBe2BO3F2 are very flat, resulting from weak s -p hybridization.

  4. Spectral studies on CuO in sodium–calcium borophosphate glasses

    Indian Academy of Sciences (India)

    S SHAILAJHA; K GEETHA; P VASANTHARANI

    2016-08-01

    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 CuO was favourable for the colour changes from light blue to dark bluish green colour. Direct optical energy bandgaps before and after doping with different percents of copper oxide obtained in the range 4.81–2.99 eV indicated the role of copper in the glassy matrix by ultraviolet (UV) spectra. The glasses have more than 80% transparency for emission wavelength range, and strong absorption bands due to the charge transition of the Cu$^+$ and Cu$^{2+}$ ions were observed. The emission bands observed in the UV and blue regions are attributed to 3d$^9$4s–3d$^{10}$ triplet transition in Cu$^+$ ion.

  5. Glass transition temperature and conductivity in Li2O and Na2O doped borophosphate glasses

    Science.gov (United States)

    Ashwajeet, J. S.; Sankarappa, T.; Ramanna, R.; Sujatha, T.; Awasthi, A. M.

    2015-08-01

    Two alkali doped Borophosphate glasses in the composition, (B2O3)0.2. (P2O5)0.3. (Na2O)(0.5-x). (Li2O)x, where x = 0.05 to 0.50 were prepared by standard melt quenching method at 1200K. Non-crystalline nature was confirmed by XRD studies. Room temperature density was measured by Archimedes principle. DC conductivity in the temperature range from 300K to 575K has been measured. Samples were DSC studied in the temperature range from 423K to 673K and glass transition temperature was determined. Glass transition temperature passed through minima for Li2O con.2centration between 0.25 and 0.30 mole fractions. Activation energy of conduction has been determined by analyzing temperature variation of conductivity determining Arrhenius law. Conductivity passed through minimum and activation passed through maximum for Li2O content from 0.25 to 0.30 mole fractions. Glass transition temperature passed through minimum for the same range of Li2O content. These results revealed mixed alkali effect taking place in these glasses. It is for the first time borophosphate glasses doped with Li2O and Na2O have been studied for density and dc conductivity and, the mixed alkali effect (MAE) has been observed.

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

    Science.gov (United States)

    Wang, Fu; Liao, Qilong; Dai, Yunya; Zhu, Hanzhen

    2016-08-01

    Immobilization of gadolinium (Gd), a nonradioactive surrogate for Pu3+, in iron borophosphate glasses/glass-ceramics (IBP glasses/glass-ceramics) has been investigated. The IBP glass containing 4 mol% Gd2O3 is homogeneously amorphous. At higher Gd2O3 concentrations, additional Gd is retained in the glasses as crystalline inclusions of monazite GdPO4 crystalline phase detected with X-ray diffraction. Moreover, Gd2O3 addition increases the Tg of the IBP glasses in glass formation range, which is consistent with the structural modification of the glasses. The structure of the Gd2O3-loaded IBP glasses/glass-ceramics is mainly based on pyrophosphate units. The chemical durability of Gd2O3-loaded IBP glasses/glass-ceramics is comparable to widely used borosilicate glass waste forms and the existence of monazite GdPO4 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 Pu3+ if the formed crystalline phase(s) have high chemical durability.

  7. Proprietes optiques non lineaires des verres borophosphates de titane ou de niobium

    OpenAIRE

    Cardinal, Thierry

    1997-01-01

    Les verres présentant des propriétés optiques non linéaires importantes constituent des candidats pour des applications de commutation optique ou de propagation soliton. Les verres du système vitreux (1 - x) (0,05Na2B4O7 - 0,95NaPO3) (x TiO2 ou x Nb2O5) ou l' oxyde de titane ou de niobium, réputés non linéaires, sont introduits en fortes proportions sont élaborés et caractérisés du point de vue optique et thermique. Une étude comparative de ces verres borophosphates de titane ou de niobium av...

  8. New bismuth borophosphate Bi4BPO10: Synthesis, crystal structure, optical and band structure analysis

    International Nuclear Information System (INIS)

    New bismuth borophosphate Bi4BPO10 was obtained by spontaneous crystallization from the melt of correspondent composition at 804 °C. Crystal structure with orthorhombic lattice parameters: a = 22.5731(3) Å, b = 14.0523(2) Å, c = 5.5149(1) Å, V = 1749.34(4), Z = 8, SG Pcab was determined by X-ray powder diffraction technique. The [Bi2O2]2+ -layers, which are typical for bismuth oxide compounds, transform into cationic endless strips of 4 bismuth atoms width directed along the c-axis in Bi4BPO10. The strips combining stacks are separated by flat triangle [BO3]3− -anions within stacks. Neighboring stacks are separated by tetrahedral [PO4]3−-anions and shifted relatively to each other. Bismuth atoms are placed in 5–7 vertex oxygen irregular polyhedra. Bi4BPO10 is stable up to 812 °C, then melts according to the peritectic law. The absorption spectrum in the range 350–700 nm was obtained and the width of the forbidden band was estimated as 3.46 eV. The band electronic structure of Bi4BPO10 was modeled using DFT approach. The calculated band gap (3.56 eV) is in good agreement with the experimentally obtained data. - Graphical abstract: Display Omitted - Highlights: • New bismuth borophosphate with composition Bi4BPO10 was synthesized. • The crystal structure was determined by X-ray powder diffraction technique. • Bismuth-oxygen part [Bi4O3]6+ forms endless strips of 4 bismuth atoms width. • Electronic structure was modeled by DFT method. • The calculated band gap (3.56 eV) is very close to the experimental one (3.46 eV)

  9. Structural and luminescence studies of europium ions in lithium aluminium borophosphate glasses

    Institute of Scientific and Technical Information of China (English)

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

    2014-01-01

    Eu3+doped borophosphate glasses with the chemical composition 20Li2O-30Al2O3-10B2O3-40P2O5-xEu2O3 (where x=0.05 mol.%, 0.1 mol.%, 1.0 mol.%, 1.5 mol.%and 2.0 mol.%) were prepared by conventional melt quenching technique. The structural and luminescence properties of the prepared Eu3+doped borophosphate glasses were studied and compared with reported results. The XRD pattern showed the amorphous nature of the prepared glasses. Whereas, the FTIR spectra revealed the vibrational modes in the prepared glasses. The bonding parameters (βandδ) were calculated through the excitation spectra. Judd-Ofelt (J-O) intensity pa-rameters were calculated from the emission spectra and were used to determine transition probability (A), stimulated emission cross-section (σEP ), radiative lifetime (τR) and branching ratios (βexp) for the transition 5D0→7Fj (j=1, 2, 3 and 4) of Eu3+ ions. Furthermore, the luminescence intensity ratio (R) of 5D0→7F2 to 5D0→7F1 transition was also calculated. Transition 5D0→7F2 had the highest value of stimulated emission cross-section and branching ratios and the results were comparable with the reported values. This indicated that the present glass is promising host material for Eu3+doped fiber amplifiers.

  10. The molten hydrated flux synthesis of a novel open-framework copper borophosphate and its structural relation with the precursors

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Long; Liu, Wei, E-mail: weiliu@ouc.edu.cn; Ma, Xiaohong; Cao, Lixin; Su, Ge; Lu, Zhisheng

    2014-10-15

    A novel copper borophosphate, Cu{sub 2}(H{sub 2}O)[BP{sub 2}O{sub 7}(OH)], has been synthesized by the molten hydrated flux method. Its crystal structure (Orthorhombic, Pbca, a=8.234 Å, b=9.655 Å, c=17.805 Å, V=1415.485 Å{sup 3}, Z=8) can be regarded as the condensation of alternately edge- and corner-shared copper pyramidal chains and borophosphate chains formed via vertex-sharing PO{sub 4} and BO{sub 3}(OH) tetrahedra. Magnetic measurements indicate that antiferromagnetic interactions exist in the title compound. Due to the special reaction medium created by the molten hydrated flux method, a possible structural correlation between final solids and raw materials has been discovered even though no ordered structural fragments exist in the latter. - Graphical: Structure comparison of Cu(NO{sub 3}){sub 2}·3H{sub 2}O, Cu(NO{sub 3}){sub 2}·H{sub 2}O and Cu{sub 2}(H{sub 2}O)[BP{sub 2}O{sub 7}(OH)], showing the structural evolution of CuO{sub 5} pyramids in the synthetic process. - Highlights: • A novel copper borophosphate has been synthesized by the molten hydrated flux method. • Magnetic measurements show its antiferromagnetism at low temperature. • A structural relation between the precursor and the final solid is discovered.

  11. Structure and chemical durability of Ce-doped iron borophosphate glasses

    International Nuclear Information System (INIS)

    The chemical durability of iron borophosphate (IBP) glasses with molar composition of 36Fe3O3-10B2O3-54P2O5 containing different contents of cerium oxide were measured by dissolution rate (DR) and product consistency test (PCT) method, the structure units and glass transition temperature (Tg) of prepared glasses were also characterized by the XRD, FTIR spectra and DTA. Monazite-typed cerium phosphate crystal was detected by XRD apparatus in the glass with molar composition of 15CeO2-30.6Fe2O3-8.5B2O3-45.9P2O5, and the glass chemical durability was also improved for the crystallization. The results analyzed by FTIR spectra show that the main glass structure units are (P2O7)4-, (PO4)3- groups and boronoxygen tetrahedron [BO4], almost without easily hydrolytic (PO3)- groups. The structure units are changed from (PO3)- groups to (P2O7)4- or (PO4)3- groups as the increase in cerium loading which also enhance the glass chemical durability. (authors)

  12. Investigations on optical properties of Sm{sup 3+} ion doped boro-phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, R.; Suthanthirakumar, P.; Karthikeyan, P.; Marimuthu, K., E-mail: mari-ram2000@yahoo.com [Department of Physics, Gandhigram Rural Institute – Deemed University, Gandhigram – 624302 (India)

    2015-06-24

    The Sm{sup 3+} doped Boro-phosphate glasses with the chemical composition 60H{sub 3}BO{sub 3}+20Li{sub 2}CO{sub 3}+10ZnO+(10−x) H{sub 6}NO{sub 4}P+xSm{sub 2}O{sub 3} (where x= 0.1, 0.5, 1 and 2 in wt%) have been prepared by melt quenching technique. The prepared glasses were characterized through optical absorption and luminescence spectral measurements. The band gap energies corresponding to the direct and indirect allowed transitions and the Urbach’s energy values were estimated from the absorption spectra. Judd-Ofelt intensity parameters have been derived to predict the radiative properties of the various emission transitions. In order to identify the emission color of the prepared glasses, the emission intensities were analyzed using CIE 1931 color chromaticity diagram. The energy transfer process takes place between Sm{sup 3+}−Sm{sup 3+} ions through cross-relaxation mechanism have also been investigated and the results were discussed and reported.

  13. White light simulation and luminescence studies on Dy3+ doped Zinc borophosphate glasses

    International Nuclear Information System (INIS)

    The Dy3+ doped Zinc borophosphate glasses with the chemical composition (79-x)B2O3+xP2O5+10Li2O+10ZnO+1Dy2O3 (where x=0, 10, 20, 30 and 50 in wt%) have been prepared by melt quenching technique. The prepared glass samples were characterized through optical absorption, emission and decay measurements. The bonding parameters, optical band gap and Urbach's energy values were calculated from the optical absorption spectra to explore the bonding nature of the Dy–O metal ligand and electronic band structure of the studied glasses. Judd–Ofelt (JO) intensity parameters were calculated from the absorption spectra by using the JO theory and it gives information about symmetry of the ligand environment around the Dy3+ ion site. The Y/B intensity ratio and radiative properties were obtained from the emission spectra and the results were compared with the reported literature. The x, y chromaticity color coordinates of the studied glasses were analyzed using a CIE 1931 color chromaticity diagram and found that the x, y coordinates lie in the white light region. The decay curve measurements of the prepared glasses exhibit non-exponential behavior and are well fitted to Inokuti–Hirayama (IH) model to understand the energy transfer mechanism between Dy3+ ions. The Q, R0 and CDA values of the prepared Dy3+ doped glasses were obtained from the IH model and the results were discussed and compared with the reported literature

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

    International Nuclear Information System (INIS)

    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 (4T1g → 6A1g). • As the concentration of Mn2+ 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 Mn2+ 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 Mn2+ 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 4T1g → 6A1g ground state of Mn2+ ions. As the concentration of Mn2+ ions increases, the emission band increases from 582 nm to 650 nm and exhibited a red light emission (octahedral symmetry). The decay curves of 4T1g level were examined for all concentrations and the measured lifetimes are found to depend strongly on Mn2+ concentrations. From the emission characteristic parameters of 6A1g (S) level, it shows that the CaZnBP glasses could have potential applications as luminescent optical materials, visible lasers and fluorescent display devices

  15. 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.

  16. The mixed former effect in lithium borophosphate oxynitride thin film electrolytes for all-solid-state micro-batteries

    International Nuclear Information System (INIS)

    The mixed former effect of boron and phosphorus is applied to improve chemical stability and electrochemical property of thin film electrolyte based on lithium phosphorus oxynitride (LiPON). This thin film with new composition ‘lithium borophosphate oxynitride (LiBPON)’ is deposited by RF magnetron sputtering with double targets of Li3PO4 and Li3BO4. When boron content is varied by controlling the RF power on Li3PO4 and Li3BO4 targets, boron ions successfully replace the four-coordinated phosphorus. Raman spectra and N 1s XPS spectra of this new electrolyte reveal that three-coordinated nitrogen atoms (P-N 2/LiBPON/Li) excellent cycling performances with the initial capacity of 34.5 μAh cm−2 and the cycling efficiency and 95.3% of its initial capacity

  17. New bismuth borophosphate Bi{sub 4}BPO{sub 10}: Synthesis, crystal structure, optical and band structure analysis

    Energy Technology Data Exchange (ETDEWEB)

    Babitsky, Nicolay A.; Leshok, Darya Y.; Mikhaleva, Natalia S. [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Kuzubov, Aleksandr A., E-mail: alexkuzubov@gmail.com [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Institute of Physics SB RAS, Krasnoyarsk 660036 (Russian Federation); Zhereb, Vladimir P. [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation); Kirik, Sergei D., E-mail: kiriksd@yandex.ru [Siberian Federal University, 79 Svobodny Av, Krasnoyarsk, 660041 (Russian Federation)

    2015-08-01

    New bismuth borophosphate Bi{sub 4}BPO{sub 10} was obtained by spontaneous crystallization from the melt of correspondent composition at 804 °C. Crystal structure with orthorhombic lattice parameters: a = 22.5731(3) Å, b = 14.0523(2) Å, c = 5.5149(1) Å, V = 1749.34(4), Z = 8, SG Pcab was determined by X-ray powder diffraction technique. The [Bi{sub 2}O{sub 2}]{sup 2+} -layers, which are typical for bismuth oxide compounds, transform into cationic endless strips of 4 bismuth atoms width directed along the c-axis in Bi{sub 4}BPO{sub 10}. The strips combining stacks are separated by flat triangle [BO{sub 3}]{sup 3−} -anions within stacks. Neighboring stacks are separated by tetrahedral [PO{sub 4}]{sup 3−}-anions and shifted relatively to each other. Bismuth atoms are placed in 5–7 vertex oxygen irregular polyhedra. Bi{sub 4}BPO{sub 10} is stable up to 812 °C, then melts according to the peritectic law. The absorption spectrum in the range 350–700 nm was obtained and the width of the forbidden band was estimated as 3.46 eV. The band electronic structure of Bi{sub 4}BPO{sub 10} was modeled using DFT approach. The calculated band gap (3.56 eV) is in good agreement with the experimentally obtained data. - Graphical abstract: Display Omitted - Highlights: • New bismuth borophosphate with composition Bi{sub 4}BPO{sub 10} was synthesized. • The crystal structure was determined by X-ray powder diffraction technique. • Bismuth-oxygen part [Bi{sub 4}O{sub 3}]{sup 6+} forms endless strips of 4 bismuth atoms width. • Electronic structure was modeled by DFT method. • The calculated band gap (3.56 eV) is very close to the experimental one (3.46 eV)

  18. Positive and Negative Mixed Glass Former Effects in Sodium Borosilicate and Borophosphate Glasses Studied by (23)Na NMR.

    Science.gov (United States)

    Storek, Michael; Adjei-Acheamfour, Mischa; Christensen, Randilynn; Martin, Steve W; Böhmer, Roland

    2016-05-19

    Glasses with varying compositions of constituent network formers but constant mobile ion content can display minima or maxima in their ion transport which are known as the negative or the positive mixed glass former effect, MGFE, respectively. Various nuclear magnetic resonance (NMR) techniques are used to probe the ion hopping dynamics via the (23)Na nucleus on the microscopic level, and the results are compared with those from conductivity spectroscopy, which are more sensitive to the macroscopic charge carrier mobility. In this way, the current work examines two series of sodium borosilicate and sodium borophosphate glasses that display positive and negative MGFEs, respectively, in the composition dependence of their Na(+) ion conductivities at intermediate compositions of boron oxide substitution for silicon oxide and phosphorus oxide, respectively. A coherent theoretical analysis is performed for these glasses which jointly captures the results from measurements of spin relaxation and central-transition line shapes. On this basis and including new information from (11)B magic-angle spinning NMR regarding the speciation in the sodium borosilicate glasses, a comparison is carried out with predictions from theoretical approaches, notably from the network unit trap model. This comparison yields detailed insights into how a variation of the boron oxide content and thus of either the population of silicon or phosphorus containing network-forming units with different charge-trapping capabilities leads to nonlinear changes of the microscopic transport properties. PMID:27092392

  19. A high-energy X-ray diffraction, 31P and 11B solid-state NMR study of the structure of aged sodium borophosphate glasses

    International Nuclear Information System (INIS)

    The structure of aged melt-quenched sodium borophosphate glasses of composition (P2O5)40(B2O3)x(Na2O)60-x (with x in the range 10-40) has been studied by high-energy X-ray diffraction (HEXRD), 31P and 11B magic angle spinning (MAS) NMR. Similar to the fresh samples, both P-O-P and P-O-B linkages are found to be present in these glasses. All three techniques show that the cross-linking between borate and phosphate units increases with boron oxide content. Distinctively upon aging, the glass is found to hydrolyze causing the network to degrade. At the same time, crystalline phases are now also observed. XRD and DTA show that the samples have a higher tendency towards crystallization with increasing boron oxide content upon exposed to moisture. 31P and 11B MAS NMR results are in agreement with these findings. TGA data show that samples with higher boron oxide content take up more moisture upon aging, suggesting that crystallization may be associated with glass hydrolysis. HEXRD results also suggest that sodium ions are preferentially associated with borate units with increasing boron oxide content

  20. Fe{sub 2.5}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, a new phosphate-borophosphate with a microporous structure

    Energy Technology Data Exchange (ETDEWEB)

    Belokoneva, E. L., E-mail: elbel@geol.msu.ru; Dimitrova, O. V. [Moscow State University, Faculty of Geology (Russian Federation)

    2015-05-15

    A new phosphate-borophosphate Fe{sub 2.5}{sup 3+}[BP{sub 2}O{sub 7}(OH){sub 2}][PO{sub 3}(OH)][PO{sub 3}(O{sub 0.5}OH{sub 0.5})] · H{sub 2}O, space group P12{sub 1}/n, is obtained under hydrothermal conditions. Blocks (Fe{sup 3+}(PO{sub 4}){sub 6}){sup 15−} consisting of vertex-sharing (Fe1,Fe2)O{sub 6} octahedra and six PO{sub 4} tetrahedra are distinguished in the structure of the new phase, which was determined without preliminary knowledge of the chemical formula. Such blocks are known for many phosphates (borophosphates), germanates, gallates, and silicates. Blocks form layers connected by BO{sub 4} tetrahedra into a framework with large pores reaching ∼9.5 Å, which are occupied by water molecules. The out-of-layer octahedral position of the Fe3 atom is split and occupied statistically. The anion radical is characterized as a phosphate-borophosphate: it consists of two isolated PO4 tetrahedra and a borophosphate soro group [BP{sub 2}O{sub 7}(OH){sub 2}] first found in NaIn[BP{sub 2}O{sub 8}(OH)]. A layer of octahedra is characterized by higher local symmetry corresponding to the orthorhombic group Pm2{sub 1}n.

  1. New zeotype borophosphates with chiral tetrahedral topology: (H)0.5M1.25(H2O)1.5[BP2O8].H2O (M=Co(II) and Mn(II))

    International Nuclear Information System (INIS)

    Two new isostructural open-framework zeotype transition metal borophosphate compounds, (H)0.5M1.25(H2O)1.5[BP2O8].H2O (M=Co(II) and Mn(II)) were synthesized by mild hydrothermal method. The structure of compounds were characterized by single-crystal X-ray diffraction which have ordered, alternating, vertex-sharing BO4, PO4, and (MO4)OM(H2O)2 groups with hexagonal, P 61 2 2 (No 178) space group and unit cell parameters for Co a=9.4960(6) A, c=15.6230(13) A, for Mn a=9.6547(12) A, c=15.791(3) A, Z=1 for both of them. TGA/DTA analysis, IR spectroscopy were used for characterization. Magnetic susceptibility measurements for both of the compound indicate strong antiferromagnetic interaction between metal centers. (copyright 2005 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Dynamic and Mechanical Properties of Calcium Borophosphate Glasses in Relation to Structure and Topology

    DEFF Research Database (Denmark)

    Hermansen, Christian; Yue, Yuanzheng

    because both end-members form glasses and the CaO/P2O5 ratio (which is related to bioactivity) varies from unity to infinity across the join. We explore the composition and structure dependence of the glass transition temperature, kinetic fragility, indentation hardness, and glass stability. We also study...

  3. An FTIR and ESR study of iron doped calcium borophosphate glass-ceramics

    Science.gov (United States)

    Karabulut, M.; Popa, A.; Borodi, G.; Stefan, R.

    2015-12-01

    A series of glasses in the xFe2O3-(100-x) [42B2O3-24CaO-34P2O5] system has been prepared for x = 0-10. Structure of as casted glasses and their heat treated counterparts have been studied by X-ray diffraction, infrared and electron spin resonance spectroscopies. Amorphous nature of all of the compositions studied is confirmed by the XRPD spectra. After the heat treatment, besides the main BPO4 phase, CaBPO5 and Ca(PO3) crystalline phases were identified in the iron free glass while B0.57Fe0.43PO4 phase was also observed in the XRD pattern of iron containing samples. FTIR spectra indicate changes in the glass network upon iron addition. X-band ESR spectra exhibits resonance signals at g ∼ 2.0 and g ∼ 4.3 for all analyzed samples. A supplementary line centered at g ∼ 6 appears after the thermal treatment. The nature of ESR absorption signals and influence of iron content on the evolution of ESR parameters are discussed.

  4. Crystallization of cerium containing iron borophosphate glasses/glass-ceramics and their spectral properties

    Science.gov (United States)

    Wang, Fu; Liao, Qilong; Zhu, Hanzhen; Dai, Yunya; Wang, Hong

    2016-04-01

    The crystallization behaviors of CeO2 containing 36Fe2O3-10B2O3-54P2O5 glasses/glass-ceramics (IBP glasses/glass-ceramics) and the effect of CeO2 addition on the structure of the IBP glasses/glass-ceramics annealed at 850 °C for 10 h were investigated by XRD, SEM and FTIR. The results show that Fe4(PO4)2O and Fe2(PO4)O phases are detected in the IBP glasses/glass-ceramics annealed at 650 °C for 10 h, and traces of FePO4 crystal is also detected when the CePO4 crystallite pre-exists in the unannealed IBP glass-ceramics. When the glasses/glass-ceramics are heat-treated at 850 °C for 10 h, Fe4(PO4)2O, Fe2(PO4)O and a small amount of FePO4 phase are detected. Meanwhile, CePO4 phase also appears in the crystallized IBP glasses/glass-ceramics containing more than 6 mol% (including 6 mol%) CeO2. Moreover, the main structural units of the crystallized glasses/glass-ceramics are [PO4] and [BO4] tetrahedron. [CeO4] tetrahedron also exists in the structure of the crystallized IBP glasses/glass-ceramics containing CeO2. CeO2 addition and the pre-existing CePO4 crystallite improve the resistance of the IBP glasses/glass-ceramics to crystallization, which makes the infrared bands associated with the vibration of [PO4] group increase in intensity and shift to high wave number.

  5. Surface degradation behaviour of sodium borophosphate glass in aqueous media: Some studies

    Indian Academy of Sciences (India)

    K V Shah; M Goswami; S Manikandan; V K Shrikhande; G P Kothiyal

    2009-06-01

    The degradation behaviour of phosphate glass with nominal composition, 40Na2O–10BaO–B2O3–(50–)P2O5, where 0 ≤ ≤ 20 mol%, was studied in water, HCl and NaOH solutions at room temperature to 60°C for different periods extending up to 300 h. These glasses were synthesized by conventional melt-quench technique. Dissolution rates were found to increase with B2O3 content in the glass. The dissolution rates for the glass having 10 mol% B2O3 were found to be 0.002 g/cm2 and 0.015 g/cm2 in distilled water and 5% NaOH solution, respectively, at room temperature after 225 h of total immersion period, whereas it increased considerably to 0.32 g/cm2 in 5% NaOH at 60°C after 225 h. However, glass samples with = 15 and 20 mol% B2O3 were dissolved in 5% HCl solution after 5 h immersion. The degradation behaviour has been correlated with the structural features present in the glass. The optical microscopy of the corroded surface revealed that the corrosion mechanism were different in acid and alkali media.

  6. A comparative study on the sintering behaviour and phase emergence of calcium borophosphate and calcium titanophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Arvind, A; Dixit, Anupam; Shrikhande, V K; Kothiyal, G P, E-mail: gpkoth@barc.gov.in [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

    2009-07-15

    Calcium-phosphate (CaP) based glasses of composition 60CaO-30P{sub 2}O{sub 5}-10B{sub 2}O{sub 3} (CaPB) and 60CaO-30P{sub 2}O{sub 5}-10TiO{sub 2} (CaPT) with high Ca/P ratio (>1.0) were prepared by quenching the melt into water. The glass frit was crystallized at temperatures in the range of 650-850deg. C and XRD revealed that at 650deg. C, the first phase to form was tetragonal {beta}-Ca{sub 2}P{sub 2}O{sub 7} followed by monoclinic {alpha}-Ca{sub 2}P{sub 2}O{sub 7} at 680deg. C. The addition of TiO{sub 2} or B{sub 2}O{sub 3} did not greatly alter the phase emergence. At the same time, when glass pellets were sintered at 600deg. C, for 2-8 hr, the B{sub 2}O{sub 3} containing samples showed better densification than the TiO{sub 2} containing samples. Incorporation of B{sub 2}O{sub 3} lowers the liquidus temperature and greatly reduces the crystallization tendency. This allows for liquid phase sintering leading to higher densification.

  7. A comparative study on the sintering behaviour and phase emergence of calcium borophosphate and calcium titanophosphate glasses

    International Nuclear Information System (INIS)

    Calcium-phosphate (CaP) based glasses of composition 60CaO-30P2O5-10B2O3 (CaPB) and 60CaO-30P2O5-10TiO2 (CaPT) with high Ca/P ratio (>1.0) were prepared by quenching the melt into water. The glass frit was crystallized at temperatures in the range of 650-850deg. C and XRD revealed that at 650deg. C, the first phase to form was tetragonal β-Ca2P2O7 followed by monoclinic α-Ca2P2O7 at 680deg. C. The addition of TiO2 or B2O3 did not greatly alter the phase emergence. At the same time, when glass pellets were sintered at 600deg. C, for 2-8 hr, the B2O3 containing samples showed better densification than the TiO2 containing samples. Incorporation of B2O3 lowers the liquidus temperature and greatly reduces the crystallization tendency. This allows for liquid phase sintering leading to higher densification.

  8. An optical and structural investigation into CdTe nanocrystals embedded into the tellurium lithium borophosphate glass matrix

    Institute of Scientific and Technical Information of China (English)

    WAGEH; S

    2010-01-01

    Cadmium telluride nanocrystals that form in the TeO2-Li2O-B2O3-P2O5 glass matrix have been synthesized and studied.They are investigated by X-ray diffraction(XRD),optical transmission and infrared spectroscopy.It has been shown that the long annealing time effect on present samples leads to the growth of CdTe nanoparticles and an increase of tellurium oxide on the surface of nanocrystallites.On the other hand,the infrared spectroscopy shows that the phosphate and borate networks of the glass matrices are modified with doping by CdTe nanoparticles.

  9. The structural properties of CdO-Bi 2 O 3 borophosphate glass system containing Fe 2 O 3 and its role in attenuating neutrons and gamma rays

    Science.gov (United States)

    Saudi, H. A.; Mostafa, A. G.; Sheta, N.; El Kameesy, S. U.; Sallam, H. A.

    2011-11-01

    A glass system with chemical formula xBi 2O 3-(30- x)CdO-10B 2O 3-20Fe 2O 3-40P 2O 5 (0≤ x≤30) wt% is prepared to be used as radiation shield. The mass attenuation coefficient and half value layer of the glass system to gamma rays have been measured experimentally and compared with those determined from theoretical calculations using the mixture rule of WinXCom program. A database of effective mass removal cross-sections for fast neutrons is also introduced in this work. The obtained results of this study are correlated to the structural properties of these glasses obtained from their IR spectra and the influence of gamma and neutrons irradiation on these structural properties.

  10. Large scale micro-structured optical second harmonic generation response imprinted on glass surface by thermal poling

    Science.gov (United States)

    Yang, G.; Dussauze, M.; Rodriguez, V.; Adamietz, F.; Marquestaut, N.; Deepak, K. L. N.; Grojo, D.; Uteza, O.; Delaporte, P.; Cardinal, T.; Fargin, E.

    2015-07-01

    Micro-structured second harmonic generation responses have been achieved on borophosphate niobium glasses by thermal poling using micro-patterned silicon substrates. The poling imprinting process has created sub-micrometer sized patterns of both surface relief and second order optical responses on the anode glass surface. Field enhancement effects within the micro structured electrode are believed to govern the charge density on the glass surface during the process and thus amplitudes of both implemented electric field and Maxwell stresses.

  11. A New Ceramic Substrate Glaze with High Resistance to Molten Aluminum

    Institute of Scientific and Technical Information of China (English)

    Ming ZHOU; Ke LI; Da SHU; Jiao ZHANG; Baode SUN; Jun WANG

    2003-01-01

    Corrosion resistance of ceramic substrate glazes to molten aluminum was studied in this paper. The glazes can spreadslightly in aluminum alloy according to SEM examination of solidified interface between the glazes and aluminumalloy. The components of B2O3-P2O5 glazes were not detected with electron probe at the side of aluminum alloynear the interface, but the components of boron-free glaze were detected. It is shown that borophosphate glazes canresist the corrosion of molten aluminum.

  12. Structure and properties of ZnO-B2O3-P2O5-TeO2 glasses

    International Nuclear Information System (INIS)

    Zinc borophosphate glasses doped with TeO2 were studied in the compositional series (100 - x)[0.5ZnO-0.1B2O3-0.4P2O5]-xTeO2 in a broad concentration range of x = 0-80 mol% TeO2. The structure of the glasses was studied by Raman and IR spectroscopy and by 31P and 11B MAS NMR spectroscopy. According to the Raman and IR spectra, TeO2 is incorporated in the structural network in the form of TeO3, TeO3+1 and TeO4 structural units. The ratio of TeO4/TeO3 increases with increasing TeO2 content in the glasses. The incorporation of TeOx units into the glass network is associated with the depolymerisation of phosphate chains, as revealed by Raman spectroscopy. The incorporation of TeO2 modifies also the coordination of boron atoms, where B(OP)4 structural units are gradually replaced by B(OP)4-n(OTe)n units. The addition of TeO2 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% TeO2, but with further additions of TeO2 it improves and the glasses with a high TeO2 content reveal better durability than the parent zinc borophosphate glass.

  13. Na2O.B2O3-Al2O3-P2O5 system as a medium for vitrification of nuclear power plant wastes

    International Nuclear Information System (INIS)

    Laboratory experiments have shown that in the studied system 3Na2O.B2O3-Al2O3-P2O5 in the area of the delineated simplex triangle it is possible to obtain glasses which are very easily melted at temperatures of approximately 1100 degC. These glasses have only a slight tendency to crystallization and a high dilatability, especially in the region of transformation. Also studied was the hydrolytical and chemical resistance of different glass samples. The pilot plant experiment verified the possibility of the fixation of radioactive wastes in material based on sodium borophosphates. (J.B.)

  14. Effect of zinc borate on the thermal degradation of ammonium polyphosphate

    International Nuclear Information System (INIS)

    The thermal behaviour of a mixture containing an ammonium polyphosphate based compound (AP760) and zinc borate (ZB) is investigated. After an investigation of the degradation of the pure components, the interactions between them are examined by thermogravimetry. Then, X-ray diffraction (XRD) and 11B and 31P solid-state nuclear magnetic resonance (NMR) measurements have been carried out on residues of mixtures of AP760 and FBZB heat treated at different characteristic temperatures. It reveals the nature of the interactions taking place between the two components. It is demonstrated that reactions lead to the formation of zinc phosphate and of borophosphates. Mechanisms of thermal degradation are proposed

  15. Ion transport studies on Li2O-PbO-B2O3-P2O5 glass system

    Science.gov (United States)

    Muralidhara, R. S.; Anavekar, R. V.

    2009-07-01

    Electrical conductivity of Li+ ion conducting borophosphate glass system with the general formula xLi2O -10PbO-(90-x) [55B2O3 + 45 P2O5] where x=20, 25, 30 and 35 has been carried out both as a function of temperature and frequency in the temperature range 303K to 503K and over frequencies 20 Hz to 12 MHz. The dc conductivities show Arrhenius behaviour while exhibiting composition dependence. Edc estimated from Arrhenius plots varies from 0.82 eV 0.88 eV. The ac conductivity behaviour has been analyzed using a single power law. The exponent `s' obtained from the power law fits is found to have values ranging from 0.45 to 0.84.in these glasses and shows moderate temperature dependence The stretched exponent β also is seen to vary slightly with temperature. Scaling behaviour also has been carried out using the reduced plots of conductivity and frequency. The time-temperature superposition of data points is found to be satisfactory indicating that the ion transport mechanism remains the same in the entire range of temperatures and compositions studied. The results have been explained considering the borophosphate network and the role of Li2O as a glass modifier.

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

    International Nuclear Information System (INIS)

    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)

  17. 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)].

  18. Effect of sodium to barium substitution on the space charge implementation in thermally poled glasses for nonlinear optical applications

    Science.gov (United States)

    Malakho, Artem; Dussauze, Marc; Fargin, Evelyne; Bidault, Olivier; Rodriguez, Vincent; Adamietz, Frederic; Poumellec, Bertrand

    2009-05-01

    Thermally poled niobium borophosphate glasses in the system 0.55(0.95- y) NaPO 3+ y/2 Ba(PO 3) 2+0.05Na 2B 4O 7)+0.45Nb 2O 5 were investigated for second order optical nonlinear (SON) properties. Bulk glasses were studied by Raman spectroscopy, thermal analysis, optical and dielectric measurements. The sodium to barium substitution does not lead to significant changes in optical properties, crystallization of glasses and coordination environment of polarizable niobium atoms. However, the ionic conductivity decreases drastically with the increase of barium concentration. Secondary ion mass spectroscopy has been used to determine the element distribution in the anode layer of the thermally poled glasses. The second order optical susceptibilities gradually decrease from χ(2)=2.8 pm/V to zero with the increase of barium content. Using a simple electrical model, variations of nonlinear optical responses have been correlated with dielectric characteristics.

  19. 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].

  20. Strain engineering of nonlinear boron phosphate for phase matching in the ultraviolet region: a first-principles study

    Science.gov (United States)

    Hu, Jinyu; Ma, Zuju; Li, Jun; He, Chao; Li, Qiaohong; Wu, Kechen

    2016-05-01

    Borophosphates, particularly BPO4 (BPO) crystals, have attracted attention in laser frequency conversion devices because of their short ultraviolet cutoff edge and relatively large second harmonic generation (SHG) response, which is almost twice as great as that of KH2PO4. However, the birefringence of BPO (approximately 0.005) is too small to satisfy the phase matching condition in the ultraviolet spectral region, restricting the laser output efficiency. Here we systematically examine the influence of mechanical strains on the atomic structure as well as the electronic and optical properties of BPO using first-principles calculations. Interestingly, we find that the birefringence of BPO can be enhanced by ~0.06 through external uniaxial strain along the c-axis. Meanwhile, compressive strain can increase the band gap and SHG coefficients effectively. Refractive-index dispersion is also emphasized in this work. Our results indicate that phase matching in the ultraviolet region (266 nm) can be achieved under  ‑10% strain (3.9 GPa). This investigation is helpful for understanding the structure–property relationship of BPO under strain, and it also indicates its possible use as a promising ultraviolet nonlinear optical crystal.

  1. Investigation of crystal structure and associated electronic structure of Sr 6BP 5O 20

    Science.gov (United States)

    Ehrenberg, Helmut; Laubach, Sonja; Schmidt, P. C.; McSweeney, R.; Knapp, M.; Mishra, K. C.

    2006-04-01

    Strontium borophosphate phosphate (Sr 6BP 5O 20, SrBP), activated by divalent europium ions is a bluish-green phosphor emitting in a broad band with the emission peak near 480 nm. In this paper, we report the crystal structure of SrBP determined from an analysis of the X-ray diffraction pattern of a prismatic single crystal (size 60 μm×50 μm×40 μm). This crystal was chosen from undoped phosphor powder samples prepared for this purpose by solid-state reaction. SrBP is observed to crystallize in a body-centered tetragonal lattice with the lattice parameters a=9.7895(7) Å and c=19.032(3) Å, the associated space group being I4¯c2 (space group 120). Using the structural data from this study, we have also calculated its electronic structure using the augmented spherical wave method and the local density approximation (LDA). We show the ordering of the electronic states by the density of states (DOS) and the partial DOS plots. The LDA gives a direct optical band gap at the Γ point of about 5 eV. The significance of the crystal structure and associated electronic structure is discussed with respect to maintenance of this phosphor in Hg-discharge lamps.

  2. Synthesis, thermal and photoluminescent properties of ZnSe- based oxyfluoride glasses doped with samarium

    International Nuclear Information System (INIS)

    Rare earth (RE) doped glasses and glass ceramic materials have recently received considerable attention because of their potential or realized applications as X-ray intensifying screens, phosphors, detectors, waveguides, lasers etc. [1]. In this work, we present a new RE doped ZnO-ZnSe-SrF2-P2O5-B2O3-Sm2O3-SmF3 (ZSPB) glass system synthesized by melt quenching technique. The resulting glasses were visually fully transparent and stable with glass the transition temperatures around 530°C. The thermal properties of this glass system were characterized by Modulated Differential Scanning Calorimetry (MDSC) measurements before and after annealing at 650°C. We have characterized these glasses by Raman spectroscopy and photoluminescence (PL) measurements over the UV-VIS range using light emitting diodes (LED) and laser diodes (LD) excitation sources. We have also irradiated thermally treated and non-treated glass samples by X-rays and have studied the resulting PL. We discuss the results in terms of previously reported models for Sm-doped Zn-borophosphate oxide, oxyfluoride and oxyselenide glasses

  3. 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)

    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.

  4. Synthesis, thermal and photoluminescent properties of ZnSe- based oxyfluoride glasses doped with samarium

    Science.gov (United States)

    Kostova, I.; Okada, G.; Pashova, T.; Tonchev, D.; Kasap, S.

    2014-12-01

    Rare earth (RE) doped glasses and glass ceramic materials have recently received considerable attention because of their potential or realized applications as X-ray intensifying screens, phosphors, detectors, waveguides, lasers etc. [1]. In this work, we present a new RE doped ZnO-ZnSe-SrF2-P2O5-B2O3-Sm2O3-SmF3 (ZSPB) glass system synthesized by melt quenching technique. The resulting glasses were visually fully transparent and stable with glass the transition temperatures around 530°C. The thermal properties of this glass system were characterized by Modulated Differential Scanning Calorimetry (MDSC) measurements before and after annealing at 650°C. We have characterized these glasses by Raman spectroscopy and photoluminescence (PL) measurements over the UV-VIS range using light emitting diodes (LED) and laser diodes (LD) excitation sources. We have also irradiated thermally treated and non-treated glass samples by X-rays and have studied the resulting PL. We discuss the results in terms of previously reported models for Sm-doped Zn-borophosphate oxide, oxyfluoride and oxyselenide glasses.

  5. Effect of B2O3 addition on microhardness and structural features of 40Na2O–10BaO–B2O3–(50–)P2O5 glass system

    Indian Academy of Sciences (India)

    K V Shah; M Goswami; M N Deo; A Sarkar; S Manikandan; V K Shrikhande; G P Kothiyal

    2006-02-01

    Phosphate glasses having composition, 40Na2O–10BaO–B2O3–(50–)P2O5, where = 0–20 mol% were prepared using conventional melt quench technique. Density of these glasses was measured using Archimedes principle. Microhardness (MH) was measured by Vicker’s indentation technique. Structural studies were carried out using IR spectroscopy and 31P and 11B MAS NMR. Density was found to vary between 2.62 and 2.77 g/cc. MH was found to increase with the increase in boron content. 31P MAS NMR spectra showed the presence of middle 2 groups and end 1 and 0 groups with P–O–B linkages. FTIR studies showed the presence of BO3 and BO4 structural units along with the depolymerization of phosphate chains in conformity with 31P MAS NMR. 11B NMR spectra showed increase in BO4 structural units with increasing boron content. The increase in MH with B2O3 content is due to the increase of P–O–B linkages and BO4 structural units as observed from MAS NMR studies resulting in a more rigid borophosphate glass networks.

  6. Silver(I diaquanickel(II catena-borodiphosphate(V hydrate, (Ag0.57Ni0.22Ni(H2O2[BP2O8]·0.67H2O

    Directory of Open Access Journals (Sweden)

    Hafid Zouihri

    2011-08-01

    Full Text Available The structure framework of the title compound, (Ag0.57Ni0.22Ni(H2O2[BP2O8]·0.67H2O, is the same as that of its recently published counterpart AgMg(H2O2[BP2O8]·H2O. In the title structure, the Ag, Ni, B and one O atom are located on special positions (sites symmetry 2. The structure consists of infinite borophosphate helical [BP2O8]3− ribbons, built up from alternate BO4 and PO4 tetrahedra arranged around the 65 screw axes. The vertex-sharing BO4 and PO4 tetrahedra form a spiral ribbon of four-membered rings in which BO4 and PO4 groups alternate. The ribbons are connected through slightly distorted NiO4(H2O2 octahedra, four O atoms of which belong to the phosphate groups. The resulting three-dimensional framework is characterized by hexagonal channels running along [001]. However, the main difference between the structures of these two compounds lies in the filling ratio of Wyckoff positions 6a and 6b in the tunnels. Indeed, in this work, the refinement of the occupancy rate of sites 6a and 6b shows that the first is occupied by water at 67% and the second is partially occupied by 56.6% of Ag and 21.6% of Ni. In the AgMg(H2O2[BP2O8]·H2O structure, these two sites are completely occupied by H2O and Ag+, respectively. The title structure is stabilized by O—H...O hydrogen bonds between water molecules and O atoms that are part of the helices.

  7. Interfacial antiwear and physicochemical properties of alkylborate-dithiophosphates.

    Science.gov (United States)

    Shah, Faiz Ullah; Glavatskih, Sergei; Höglund, Erik; Lindberg, Mats; Antzutkin, Oleg N

    2011-04-01

    Boron compounds have become of interest in tribology because of their unique tribochemical and tribological properties. At the same time, dialkyldithiophosphates (DTPs) of transition metals have been extensively used as multifunctional additives in lubricants to control friction and reduce wear in mechanical systems. Because of the environmental pollution and health hazards of these compounds, ashless compounds with reduced amounts of sulfur and phosphorus are desirable. This work reports on the synthesis, characterization, and tribological properties of a new class of compounds, alkylborate-dithiophosphates. This class combines two high-iron-affinity surface active groups, borate and dialkyldithiophosphate, into a single molecule. The final products, viscous liquids, were characterized by FT-IR, multinuclear (1)H, (13)C, (31)P, and (11)B NMR spectroscopy and thermal analyses. Residues of one representative compound from this class, DPB-EDTP, after thermal analyses were additionally characterized by multinuclear (13)C, (31)P and (11)B MAS and (31)P CP/MAS NMR spectroscopy. Solid-state NMR data suggest that a dominant part of the solid residue of DPB-EDTP consists of borophosphates. Antiwear and friction properties of a mineral oil with these novel additives were evaluated in a four-ball tribometer in comparison with O,O'-di-n-butyl-dithiophosphato-zinc(II), Zn-BuDTP, as a reference lubricant additive. The surface morphology and the elemental composition of the tribofilms were characterized using scanning electron microscopy with energy-dispersive X-rays spectroscopy (SEM/EDS). The results show that alkylborate-dithiophosphates, with substantially reduced amounts of sulfur and phosphorus compared with Zn-BuDTP, have considerably better antiwear and friction performance. PMID:21381776

  8. Fixation of Simulated Highly Radioactive Wastes in Glassy Solids

    International Nuclear Information System (INIS)

    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)2, NaOH, and MgO. Bulk densities varied from 2.36 to 2.90 g/cm3 for TBP-25 and from 2.63 to 2.80 g/cm3 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°C and from 830 to 975°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° at 320° F to 1.6 at 1050°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 on TBP-25 waste and from 8 to 140 mil/ month on Purex waste. Operation