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Sample records for borophosphates

  1. Structural and topological aspects of borophosphate glasses and their relation to physical properties

    DEFF Research Database (Denmark)

    Hermansen, Christian; Youngman, R.E.; Wang, J.;

    2015-01-01

    We establish a topological model of alkali borophosphate and calcium borophosphate glasses that describes both the effect of the network formers and network modifiers on physical properties. We show that the glass transition temperature (Tg), Vickers hardness (HV), liquid fragility (m) and isobaric...

  2. A Novel Borophosphate Coordination Polymer with Sandwich-type Supramolecular Architecture

    Institute of Scientific and Technical Information of China (English)

    Mao Feng LI; Heng Zhen SHI; Yong Kui SHAN; Ming Yuan HE

    2004-01-01

    A novel borophosphate (Hmel)3{Co2[(mel)2(HPO4)2(PO4)](H3BO3·H2O} (mel = melamine) has been synthesized under mild solvothermal conditions. The structure of the compound exists a high ordered organic-inorganic sandwich-type supramolecular architecture via metal-coordination, hydrogen bonds and π-π stacking interactions.

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

    DEFF Research Database (Denmark)

    Hermansen, Christian; Yue, Yuanzheng

    Calcium borophosphate glasses and glass ceramics are of interest as bone-replacement implants as they can bond to bone through an apatite layer, and dissolve in vitro at a rate comparable to the growth rate of natural bone. We investigate the pseudo-binary join between CaO•P2O5 and CaO•2B2O3...

  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. Synthesis and characterization of zinc borophosphates with ANA-zeotype framework by the microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu, E-mail: songyu@dlpu.edu.cn [Dalian Polytechnic University, Dalian 116034 (China); Ding, Ling; An, Qingda; Zhai, Shangru [Dalian Polytechnic University, Dalian 116034 (China); Song, Xiaowei [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China)

    2013-06-15

    Zinc borophosphate (NH{sub 4}){sub 16}[Zn{sub 16}B{sub 8}P{sub 24}O{sub 96}] (denoted as ZnBP-ANA) with ANA-zeotype structure has been synthesized by employing microwave-assisted solvothermal synthesis in the reaction system ZnCl{sub 2}∙6H{sub 2}O-(NH{sub 4}){sub 2}HPO{sub 4}–H{sub 3}BO{sub 3} using ethylene glycol as a co-solvent. The influences of various experimental parameters, such as reaction temperature, solvent ratio, zinc precursors and reactive power, have been systematically investigated. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA), and so on. Small and homogeneous ZnBP-ANA single crystal with regular cube morphology are crystallized by using microwave solvothermal synthesis method within a shorter time, and its grain size decreases with power. - Graphical abstract: Tailor-made ANA zeolites with varied size can be prepared by simply changing the reaction power. - Highlights: • Zinc borophosphate zeolites with ANA-zeotype structures were prepared by microwave technique. • The size of crystals could be controlled by tuning power. • Synthesis period can be significantly reduced by raising reaction temperature.

  7. 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.

  8. Concentration dependent spectroscopic properties of Dy3+ ions doped boro-phosphate glasses

    Science.gov (United States)

    Mariyappan, M.; Marimuthu, K.

    2016-05-01

    Dy3+ ions doped boro-phosphate glasses have been synthesized by melt quenching method and characterized through FTIR, absorption and luminescence spectral measurements. The presence of various stretching and bending vibrations of different borate and phosphate groups were identified from the FTIR spectra. In order to examine the electronic band structure of the studied glasses, Optical energy gap (Eopt) and Urbach energy (ΔE) values were estimated from the absorption spectra. The Judd-Ofelt (JO) intensity parameters were calculated to examine the symmetry of the ligand environment around the Dy3+ ions site. The emission spectra exhibit two intense emission bands at around 482 nm (blue) and 574 nm (yellow) corresponding to the 4F9/2→6H15/2 and 4F9/2→6H13/2 transitions respectively. The emission spectra were characterized through Commission International d'Eclairage (CIE) 1931 chromaticity diagram to explore its suitability for WLED applications.

  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. White light emission from Dy3+ doped sodium-lead borophosphate glasses under UV light excitation

    Science.gov (United States)

    Kiran, N.; Suresh Kumar, A.

    2013-12-01

    Sodium-lead borophosphate glasses doped with different Dy3+ concentrations have been prepared and characterized through, XRD, FTIR, optical absorption and photoluminescence techniques. FTIR spectrum indicates the presence of BO3 and PO4 structural units. The optical absorption spectrum has been studied at room temperature and several bands have been observed. These bands have been assigned to the ground state 6H15/2 to several excited states. The bonding parameters have been evaluated based on the observed band positions. From the absorption spectrum, Judd-Ofelt (J-O) intensity parameters have been evaluated. By using J-O parameters radiative parameters such as transition probabilities, branching ratios and absorption cross section have been evaluated. The emission spectra have been studied for different concentrations of Dy3+ ions. The yellow/blue values due to 4F9/2 → 6H13/2/4F9/2 → 6H15/2 luminescence intensity ratios of Dy3+ ions, increase with increasing concentrations, suggesting higher asymmetry and more covalent bonding character between Dy and oxygen ligands. The chromaticity coordinates were calculated from emission spectra and analysed with Commission International deI'Eclarige Color diagram. The life time of the 4F9/2 level has been measured and found to decrease with increase in Dy3+ ions concentration.

  11. Intermediate length scale organisation in tin borophosphate glasses: new insights from high field correlation NMR.

    Science.gov (United States)

    Tricot, G; Saitoh, A; Takebe, H

    2015-11-28

    The structure of tin borophosphate glasses, considered for the development of low temperature sealing glasses or anode materials for Li-batteries, has been analysed at the intermediate length scale by a combination of high field standard and advanced 1D/2D nuclear magnetic resonance techniques. The nature and extent of B/P mixing were analysed using the (11)B((31)P) dipolar heteronuclear multiple quantum coherence NMR sequence and the data interpretation allowed (i) detecting the presence and analysing the nature of the B-O-P linkages, (ii) re-interpreting the 1D (31)P spectra and (iii) extracting the proportion of P connected to borate species. Interaction between the different borate species was analysed using the (11)B double quantum-simple quantum experiment to (i) investigate the presence and nature of the B-O-B linkage, (ii) assign the different borate species observed all along the composition line and (iii) monitor the borate network formation. In addition, (119)Sn static NMR was used to investigate the evolution of the chemical environment of the tin polyhedra. Altogether, the set of data allowed determining the structural units constituting the glass network and quantifying the extent of B/P mixing. The structural data were then used to explain the non-linear and unusual evolution of the glass transition temperature.

  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 Dy{sup 3+} doped Zinc borophosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Vijayakumar, R. [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India); Venkataiah, G. [Department of Physics, Sri Venkateswara University, Tirupati 517502 (India); Marimuthu, K., E-mail: mari_ram2000@yahoo.com [Department of Physics, Gandhigram Rural University, Gandhigram 624302 (India)

    2015-01-15

    The Dy{sup 3+} doped Zinc borophosphate glasses with the chemical composition (79-x)B{sub 2}O{sub 3}+xP{sub 2}O{sub 5}+10Li{sub 2}O+10ZnO+1Dy{sub 2}O{sub 3} (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 Dy{sup 3+} 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 Dy{sup 3+} ions. The Q, R{sub 0} and C{sub DA} values of the prepared Dy{sup 3+} doped glasses were obtained from the IH model and the results were discussed and compared with the reported literature.

  14. Color tuning of Eu-Tb co-doped borophosphate glasses for white light through valence state adjustment

    Institute of Scientific and Technical Information of China (English)

    XU Suo-cheng; ZHENG Xi; TIAN Hua; LV Tian-shuai; WANG Peng; WANG Da-jian

    2011-01-01

    The dependence of color points of white light on the composition of borophosphate glasses co-doped with europium (Eu) and terbium (Tb) has been investigated in terms of valence change of rare earth ions.Under ultraviolet (UV) excitation,the white light is observed to be from a combination of 4f65d → 4f7band transition emission at 425 nm for Eu2+,5D0 → 7FJ (J=-l,2) lineemissions at 593 nm and 611 nm for Eu3+,and 5D4 → 7F5 band transition emission at 545 nm for Tb3+.By varying the glass composition,the resultant emission color can be tuned efficiently.Eventually,the optimized white light with commission intemational de l'Eclairage (CIE) coordinate of (0.3382,0.2763) and the correlate color temperature (CCT) at 5010 K are achieved.

  15. 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)

  16. One-pot synthesis of tin-borophosphate-carbon composites as anode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Mouyane, Mohamed [Institut Charles Gerhardt, UMR 5253 CNRS, Université de Montpellier, CC 1502, 34095 Montpellier Cedex 5 (France); LUSAC (EA 4253), Université de Caen Basse Normandie, 50130 Cherbourg-Octeville (France); Jumas, Jean-Claude; Olivier-Fourcade, Josette [Institut Charles Gerhardt, UMR 5253 CNRS, Université de Montpellier, CC 1502, 34095 Montpellier Cedex 5 (France); Cassaignon, Sophie [UPMC (UMR7574 CNRS), Chimie de la Matière Condensée de Paris (France); Collège de France, 11 place Marcelin Berthelot, 75231 Paris Cedex 05 (France); Jordy, Christian [SAFT, Direction de la Recherche, 111–113 Bd Alfred Daney, 33074 Bordeaux (France); Lippens, Pierre-Emmanuel, E-mail: lippens@univ-montp2.fr [Institut Charles Gerhardt, UMR 5253 CNRS, Université de Montpellier, CC 1502, 34095 Montpellier Cedex 5 (France)

    2016-01-15

    Sn{sub x}(Ca{sub 0.05}B{sub 0.975}P{sub 0.975}O{sub 3.95}){sub 1−x}/C composites as anode material for Li-ion batteries, with x=0.83 and x=0.71 were synthesized by a facile route including cellulose as carbon source. The composites were characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy and {sup 119}Sn Mössbauer spectroscopy. In the latter case, different tin phases were found in the composite including the Sn{sup II}-based amorphous interface between metallic tin and borophosphate particles that improves the dispersion of the active species. The best electrochemical performances were obtained for x=0.71 that were further improved by ball-milled the composite with a small amount of carbon black. - Graphical abstract: {sup 119}Sn Mössbauer spectra of Sn{sub x}(Ca{sub 0.05}B{sub 0.975}P{sub 0.975}O{sub 3.95}){sub 1−x}/C composites with x=0.83 (a) and x=0.71 (b).

  17. Synthesis, Structure, Thermal and Magnetic Properties of a New Open-framework Borophosphate: NH4Mn(H2O)2BP2O8·H2O

    Institute of Scientific and Technical Information of China (English)

    SHI,Heng-Zhen; CHANG,Jia-Zhong; TANG-BO,HeJin; DING,Han-Ming; SHAN,Yong-Kui

    2006-01-01

    Using new template agent, a new borophosphate compound, NH4Mn(H2O)2BP2Os·H2O was hydrothermally prepared and structurally characterized. It crystallizes in a hexagonal space group P6122 with lattice parameters a=0.9652(2) nm, c=1.5792(5) nm, V=1.2740(5) nm3 and Z=6. The structure has a three-dimensional open-frame work with borophosphate helical ribbons 1∞{[BP2O8]3-} and MnO4(H2O)2 octahedra. The water molecules are positioned inside the helical channels. Very interestingly, the ammonium ions are located outside the loop of the free helical ribbons via the strong hydrogen bonds, which is different from the borophosphate analogue reported.The magnetization of the title compound is paramagnetic down to 5 K of the Curie-Weiss type within the measured range of 5-300 K with θ= -7.3 K, indicative of very weak antiferromagnetic interactions. The thermal decomposition of the compound was also described.

  18. Low-temperature flux syntheses and characterizations of two 1-D anhydrous borophosphates: Na 3B 6PO 13 and Na 3BP 2O 8

    Science.gov (United States)

    Xiong, Ding-Bang; Chen, Hao-Hong; Yang, Xin-Xin; Zhao, Jing-Tai

    2007-01-01

    Two new anhydrous sodium borophosphates with one-dimensional structure, Na 3B 6PO 13(1) and Na 3BP 2O 8(2), were synthesized by low-temperature molten salts techniques using boric acid and sodium dihydrogen phosphate as flux, respectively. The crystal structures were solved by means of single-crystal X-ray diffraction ( 1, orthorhombic, Pnma (no. 62), a=9.3727(4) Å, b=16.2307(7) Å, c=6.7232(3) Å, Z=4; 2 , monoclinic, C2/ c (no. 15), a=12.567(4) Å, b=10.290(3) Å, c=10.210(3) Å, β=92.492(5)°, Z=8). Compound 1 is characterized by an infinite chain of ∞1{[BPO]} containing eight-membered rings in which all vertexes of borate groups contribute to interconnection. Compound 2 reveals an infinite straight chain ∞1{[BPO]} built of vertex-sharing four-membered rings, and chains in neighboring layers arranged along different orientations. The relations between structures and the synthetic conditions with only traced water are discussed.

  19. 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.

  20. 过渡金属和主族元素硼磷酸盐体系的研究%Investigations on Transition-metal and Main-group-element Borophosphate Systems

    Institute of Scientific and Technical Information of China (English)

    宓锦校; 黄雅熙; 赵景泰; 毛少瑜; 李满荣

    2001-01-01

    总结了作者近几年在硼磷酸盐研究中所合成和表征的10多个新化合物,即元素周期表第4周期从Cr至Ga的元素或氧化物与工业催化剂材料BPO.在高温固相反应中,分别合成出具有3种结构类型的新化合物:新结构类型的三方Cr2[BP3O12]、正交AlPO4型的(B,M)[PO4](M=Mn,Fe.Co,Ni,Cu,Zn)和新型四方(Ga,B)PO4;用水热法合成出NaGa[BP2O7(OH)3]、Na2In2[PO3(OH)]4·H2O和Na4Co3H2(PO4)4·8H2O等新化合物.同时还讨论了硼磷酸盐化合物研究的最新进展及结构化学的一般规律.%Borophosphates have attracted much attention of scientists in the last few years due to the potential applications of these compounds as functional materials. More than ten new compounds in the related systems have been synthesized and characterized here by either solid state reactions or hydrothermal methods. The new compounds have either new structure types like Cr2BP3O12 which contains new building motif, or with very well known structure type like low cristobalite. The general structural features of these compounds have been discussed together with the literature data, and the new developments of the borophosphate research have also been reviewed here.

  1. Crystal Structure of Borophosphate with 61 Screw Axis Helices

    Institute of Scientific and Technical Information of China (English)

    石恒真; 单永奎; 戴立益; 刘煜炎; 翁林红

    2003-01-01

    A brilliant purple octahedral single crystal is hydrothermally synthesized by the reaction of CoCl2·6H2O, H3BO3 and H3PO4 in NaOH aqueous solution of CH3(CH2)15N(CH3)3Br, and its crystal structure has been characterized by single-crystal X-ray diffraction. The compound, NaCo(H2O)2BP2O8·H2O (Mr = 336.72), belongs to hexagonal, space group P6122 with a = 9.447(5), c = 15.83(1) (A。), V = 1223(1) (A。)3, Dc = 2.742 g/cm3, Z = 6, F(000) = 1002 and β= 2.606 mm-1. The three-dimensional framework in the compound is built up from the linkage tetrahedral ribbons, in which the BO4 and PO4 tetrahedra alternate with CoO6 octahedra. The sodium ions and water molecules are located within the free thread of the helical ribbons.

  2. 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.

  3. Investigations of structure and transport in lithium and silver borophosphate glasses

    Science.gov (United States)

    Kumar, Sundeep; Vinatier, Philippe; Levasseur, Alain; Rao, K. J.

    2004-04-01

    Glasses in the system xLi 2O·(1- x)[0.5B 2O 3·0.5P 2O 5] and xAg 2O·(1- x)[0.5B 2O 3·0.5P 2O 5] have been prepared from melt quenching method. Glasses have been characterized for their densities, molar volumes, glass transition temperatures and heat capacities. Structural studies have been done using infrared and high resolution magic angle spinning nuclear magnetic resonance (HR MAS NMR) of 31P, 11B and 7Li nuclei. Boron is present only in tetrahedral coordination except in Li 2O-rich glasses. Transport properties have been investigated over a wide range of frequency and temperature. Silver containing glasses are found to possess higher conductivities and lower barriers than lithium containing glasses. A structural model has been proposed in which pure B 2O 3-P 2O 5 compositions are assumed to be constituted of BPO 4 units and modification occurs selectively on the phosphate moiety. Tetrahedral boron units are thus expected to be retained in the glass structure.

  4. 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.

  5. Open-framework Borophosphate:(NH4)0.5FeⅡ0.5FeⅢ0.5·(H2O)2 BP2O8·0.5 H2O

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    An open-framework ammonium ferricborophosphate compound was synthesized by mild hydrothermal condition at 110°C. The crystal structure has been determined by single-crystal X-ray diffraction analysis: hexagonal, P6522, a = 9.452(2)A, c = 15.698(5)A,α = 90°,γ = 120°,Z= 6, Mr = 310.58, V = 1214.0(5)A3, Dc = 2.549 g/cm3, μ= 2.311mm-1, F(000) = 930. The chiral tetrahedral-tetrahedral helical ribbons are linked by the mixed valance FeII/FeIIIO6 coordinated octahedra. The ammonium ions are located inside the free loop of helical ribbons close to the inner wall of the helical channels{[BP2O8]3-}, effecting on balancing charge and stabilizing helical ribbons.

  6. Investigation on Structures and Properties of Yb3+-Doped Laser Glasses

    Institute of Scientific and Technical Information of China (English)

    Liu Shujiang; Lu Anxian; Tang Xiaodong; He Shaobo

    2006-01-01

    The Yb3+-doped silicate, phosphate and borophosphate laser glasses were prepared by means of conventional melt quenching technology.The physical and spectral properties of the glasses were investigated.The results show that, due to the existence of OH-, the fluorescence lifetime of phosphate glass is shorter than that of silicate glass, so silicate glass has better spectral properties than phosphate glass.Silicate glass has better mechanical and thermal properties than phosphate glass, but with the addition of B2O3, mechanical and thermal properties of phosphate glass are improved greatly without fluorescence quenching effect.This kind of borophosphate glass can be used in high average power solid state lasers.

  7. 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.

  8. MPS/CAS Cooperation on Solid State Chemistry

    Institute of Scientific and Technical Information of China (English)

    Zhao Jingtai; Rüdiger Kniep

    2004-01-01

    @@ The cooperation between Zhao Jingtai and the Max Planck Institute for Chemical Physics of Solids was initiated immediately after the research field Inorganic Chemistry (headed by Rüdiger Kniep) started its work in Dresden. The first contact was established when Zhao Jingtai came from the Xiamen University as a Max Planck fellow. At that time, the chemistry of the intermetallic compounds of rare-earth metals was chosen as a topic of joint investigations with Yuri Grin. Later, the solid state chemistry of the borophosphates was added to the program of concerted research in the group of Zhao Jingtai and the Max Planck Institute for Chemical Physics of Solids.

  9. Na5(NH4Mn3[B9P6O33(OH3]·1.5H2O

    Directory of Open Access Journals (Sweden)

    Rüdiger Kniep

    2008-12-01

    Full Text Available The overall hexagonal framework of the title compound, pentasodium ammonium trimanganese(II borophosphate sesquihydrate, consists of tube-like borophosphate anions, ∞1{[B3P2O11(OH]4−}, made up of corner-sharing PO4 and BO4 tetrahedra and BO2(OH triangles, forming ten-membered ring windows. The tubes are interconnected via distorted MnO6 octahedra, establishing a three-dimensional open-framework structure with two different types of ring-channels (12- and six-membered that run along [001]. The 12-membered ring channels are occupied by NH4+ ions and water molecules. The ten-membered ring windows in the walls of the tubes are occupied by Na+ ions. The remaining Na+ ions and the water molecules, one of which is half-occupied, reside within the six-membered ring channels. The structural setup is consolidated by an O—H...O hydrogen bond between the OH group and an opposite O atom of the framework. Donor–acceptor distances ranging from 2.80 to 3.35 Å between the ammonium N atom, water O atoms and framework O atoms indicate further hydrogen-bonding interactions.

  10. Electrochemical mechanisms in tin-containing composite materials for negative electrodes in Li-ion batteries: Transformation of the interfacial tin species during the first galvanostatic discharge of Sn[BPO 4] 0.4

    Science.gov (United States)

    Conte, Donato E.; Stievano, Lorenzo; Olivier-Fourcade, Josette; Jumas, Jean-Claude; Willmann, Patrick

    The Sn[BPO 4] 0.4 composite material is composed of three main constituents: the electrochemically active Sn 0 species, the BPO 4 buffer matrix, and an interfacial amorphous Sn II borophosphate phase which acts as a link between the other two, improving the cohesion of the whole composite. In this paper, we report an investigation of the effect of the reaction time on structure and size of this interfacial layer formed between the Sn 0 and the BPO 4 particles. 119Sn Mössbauer spectroscopy shows an increase in the amount of the oxidized Sn II species with the increase of the reaction time following a quasi-kinetic profile. Operando Mössbauer spectroscopy allowed the study of the transformation of the interface at the beginning of the first electrochemical cycle, indicating that the big irreversible loss during the first discharge is closely related to the increase of the amount of Sn II in the amorphous interface.

  11. 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].

  12. Emission color variation of (Ba,Sr)3BP3O12:Eu2+ phosphors for white light LEDs.

    Science.gov (United States)

    Kuo, Te-Wen; Liu, Wei-Ren; Chen, Teng-Ming

    2010-02-01

    A series of alkaline earth borophosphate phosphors, (Ba,Sr)(3)BP(3)O(12) doped with Eu(2+) ions, were synthesized by a solid state reaction. Two emission bands at 465 nm and 520 nm were attributed to the f-d transitions of doped Eu(2+) ions occupying in two different cation sites in host lattices and emission color variation was observed by substituting the M(2+) sites, which was rationalized in terms of two competing factors of the crystal field strength and bond covalence. Green and bluish-white pc-LEDs were fabricated by combination of a 370 nm near-UV chip and composition-optimized Ba(3)BP(3)O(12):Eu(2+) and (Ba,Sr)(3)BP(3)O(12):Eu(2+) phosphors, respectively. The series of phosphors may serve as a promising green and bluish-white luminescent materials used in fabrication of near UV-based white pc-LEDs.

  13. Influence of addition of B2O3 on properties of Yb3+ -doped phosphate laser glass

    Institute of Scientific and Technical Information of China (English)

    LIU Shu-jiang; LU An-xian; TANG Xiao-dong; HE Shao-bo

    2006-01-01

    The three host glasses doped with Yb3+ were prepared by means of conventional melt quenching technol ogy, and the influence on physical and spectral properties of phosphate glass due to addition of B2O3 was investigated and compared with silicate glass. The results show that due to the existence of OH- impurities which induce thenon-radiative route, the fluorescence lifetime of phosphate glass is shorter, so silicate glass has better spectral properties than phosphate glass. Silicate glass has more excellent thermal-mechanical properties than phosphate glass,but with the addition of B2O3, thermal-mechanical properties of phosphate glass are improved greatly without fluo rescence quenching effect, and this kind of borophosphate glass will be the candidate to be used in high average pow er solid state laser.

  14. Sn-0.4BPO 4 composite as a promising negative electrode for rechargeable lithium batteries

    Science.gov (United States)

    Aboulaich, Abdelmaula; Womes, Manfred; Olivier-Fourcade, Josette; Willmann, Patrick; Jumas, Jean-Claude

    2010-01-01

    The structural and textural properties of a Sn-0.4BPO 4 composite material synthesized by ex situ dispersion of β-Sn in a BPO 4 matrix were investigated by using several complementary techniques to study the global order (XRD, TGA-DSC, SEM-XEDS) and the local order (FT-IR, 119Sn Mössbauer spectroscopy and X-ray absorption spectroscopy). The results reveal that the composite material consists of three main components: an electrochemically active species "Sn", an inactive matrix "BPO 4", and an amorphous Sn(II) borophosphate which acts as a link between the two former and which improves the cohesion of the composite. The electrochemical performances of the composite material were tested in Swagelok-type cells with metallic Li as counter-electrode. It shows a high reversible capacity of about 500 mAh g -1 at a C/20 rate, and a very good stability under cycling even at very fast rates of C or C/1.3.

  15. 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.

  16. 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.

  17. 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.

  18. Crystal structure of ABPO5 and optical study of Pr3+ embedded in these compounds

    Science.gov (United States)

    Ben Ali, A.; Antic-Fidancev, E.; Viana, B.; Aschehoug, P.; Taibi, M.; Aride, J.; Boukhari, A.

    2001-10-01

    The crystal structure of borophosphates ABPO5 (A = alkaline earth or Pb) was resolved on a polycrystalline sample using the Rietveld method. The x-ray diffraction patterns data show that ABPO5 crystallize in a centrosymmetric space group P3121 and their structure is related to the borogermanates REBGeO5 with a stillwellite-type structure. Pr3+ ion was used as a local structural probe to corroborate the structural resolution results. Absorption and fluorescence spectra of A1-xPrxBP1-xGexO5 (A = alkaline earth or Pb; x = 0.05) have been investigated at different temperatures. At 9 K the 3H4 → 3P0 transition of trivalent praseodymium ion (4f2 configuration) is observed as a single line. This indicates a unique crystallographic site for the rare earth ion in these compounds replacing the divalent cation. Energy level schemes were deduced from the low-temperature spectroscopic measurements. Comparing the electronic level splittings of studied compounds with the already reported data on REBGeO5 doped with Pr3+ ion, it is possible to dispel the doubt existing about structural determination. Moreover, under 460 nm excitation, intense red emission of trivalent praseodymium is observed corresponding to 1D2 → 3H4 transition. The lifetime measurements of 1D2 level have been performed for all the title compounds.

  19. Silver diaquacobalt(II catena-borodiphosphate(V hydrate, (Ag0.79Co0.11Co(H2O2[BP2O8]·0.67H2O

    Directory of Open Access Journals (Sweden)

    Hafid Zouihri

    2012-01-01

    Full Text Available The structure of the title compound, (Ag0.79Co0.11Co(H2O2[BP2O8]·0.67H2O is isotypic to that of its recently published counterparts AgMg(H2O2[BP2O8]·H2O and (Ag0.57Ni0.22Ni(H2O2[BP2O8]·0.67H2O. It consists of infinite borophosphate helical ribbons [BP2O8]3−, 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-membred rings in which BO4 and PO4 groups alternate. The ribbons are connected through slightly distorted CoO4(H2O2 octahedra whose four O atoms belong to the phosphate groups. The resulting three-dimensional framework is characterized by hexagonal channels running along [001] in which the remaining water molecules are located. The main difference between the Mg-containing and the title structure lies in the filling ratio of Wyckoff positions 6a and 6b in the tunnels. The refinement of the occupancy rate of the site 6a shows that it is occupied by water at 67%, while the refinement of that of the site 6b shows that this site is partially occupied by 78.4% Ag and 10.8% Co, for a total of 82.2%. The structure is stabilized by O—H...O hydrogen bonds between water molecules and O atoms that are part of the helices.

  20. 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.

  1. Sn x[BPO 4] 1-x composites as negative electrodes for lithium ion cells: Comparison with amorphous SnB 0.6P 0.4O 2.9 and effect of composition

    Science.gov (United States)

    Conte, Donato Ercole; Aboulaich, Abdelmaula; Robert, Florent; Olivier-Fourcade, Josette; Jumas, Jean-Claude; Jordy, Christian; Willmann, Patrick

    2010-01-01

    A comparative study of two Sn-based composite materials as negative electrode for Li-ion accumulators is presented. The former SnB 0.6P 0.4O 2.9 obtained by in-situ dispersion of SnO in an oxide matrix is shown to be an amorphous tin composite oxide (ATCO). The latter Sn 0.72[BPO 4] 0.28 obtained by ex-situ dispersion of Sn in a borophosphate matrix consists of Sn particles embedded in a crystalline BPO 4 matrix. The electrochemical responses of ATCO and Sn 0.72[BPO 4] 0.28 composite in galvanostatic mode show reversible capacities of about 450 and 530 mAh g -1, respectively, with different irreversible capacities (60% and 29%). Analysis of these composite materials by 119Sn Mössbauer spectroscopy in transmission (TMS) and emission (CEMS) modes confirms that ATCO is an amorphous Sn II composite oxide and shows that in the case of Sn 0.72[BPO 4] 0.28, the surface of the tin clusters is mainly formed by Sn II in an amorphous interface whereas the bulk of the clusters is mainly formed by Sn 0. The determination of the recoilless free fractions f (Lamb-Mössbauer factors) leads to the effective fraction of both Sn 0 and Sn II species in such composites. The influence of chemical composition and especially of the surface-to-bulk tin species ratio on the electrochemical behaviour has been analysed for several Sn x[BPO 4] 1-x composite materials (0.17BPO 4] 0.28 as active material exhibits interesting electrochemical performances (reversible capacity of 500 mAh g -1 at C/5 rate).

  2. Enhanced luminescence behaviour of Eu3+ doped heavy metal oxide telluroborate glasses for Laser and LED applications

    Science.gov (United States)

    Pravinraj, S.; Vijayakumar, M.; Marimuthu, K.

    2017-03-01

    Effect on structural and spectroscopic behaviour caused by the replacement of lead cations with the aluminium cations in the Eu3+ doped heavy metal oxide borophosphate glasses have been studied with the chemical composition (55B2O3+19.5TeO2+10K2O+(15-x)PbO+xAl2O3+0.5Eu2O3 (where x=0, 2.5, 5, 7.5, 10, 12.5 and 15 in wt%) prepared by melt quenching technique. The FTIR and Raman spectral studies reveal the presence of various fundamental vibrational units and are used to identify the phonon energy of the title glasses. The positive values of bonding parameter (δ) indicate the formation of covalent bonds between the dopant (Eu3+) and the anions (O2-). Luminescence spectra of all the titled glasses exhibit five emission bands due to the electronic transitions of the trivalent europium ions. The radiative properties such as transition probability (A), stimulated emission cross-section (σpE) and branching ratio (βR) of the various emission transitions of the Eu3+ ions have been estimated using Judd-Ofelt (JO) theory. The characteristic emission was identified through CIE 1931 color chromaticity diagram and McCamy's formula have been used to estimate the correlated color temperature (CCT) using (x,y) chromaticity coordinates. The luminescence decay profile pertaining to the 5D0 metastable state of the Eu3+ ions exhibits single exponential behaviour uniformly for all the titled glasses and the experimental lifetime values were obtained following the curve fitting method.

  3. 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.