Metaphosphate Glasses Research Articles

Cu katkılı NaPO3 camlarının sentez ve karakterizasyonu

Sunulan çalışma, NaPO3 (sodyum metafosfat ya da sodyum fosfat) camlarının yapısal ve morfolojik özellikleri üzerinde, Cu katkısının etkilerinin incelenmesini amaçlamaktadır. Farklı oranlarda Cu katkısı içeren NaPO3 camları 700 °C’de sentezlendi. Sentezlenen camların karakterizasyon işlemi Fourier dönüşümlü kızılötesi (FTIR), X-ışını kırınımı (XRD) ve taramalı elektron mikroskopisi (SEM) ile gerçekleştirildi. Üretilen numunelerin sahip oldukları tek fazın ortorombik kristal yapıdaki NaPO3 olduğu belirlendi. Ayrıca, Cu katkısının üretilen sodyum fosfat camlarının kristalleşme miktarı, kristal büyüklüğü ve örgü parametrelerinde önemli değişimlere sebep olduğu gözlendi. Üretilen sodyum fosfat camlarının morfolojisinin Cu katkılanmasıyla etkilendiği belirlendi.

Calculations of Avrami exponent and applicability of Johnson–Mehl–Avrami model on crystallization in Er:LiY(PO3)4 phosphate glass

Preparation and thermal properties of Er3+-doped lithium–yttrium meta-phosphate glasses with a nominal composition of Er:LiY(PO3)4 were studied as a new scintillating material for neutron detection. The glassy Er:LiY(PO3)4 ingots 10 × 10 × 25 mm3 in size were prepared by quenching of the molten mixture of the starting lithium carbonate, yttrium phosphate, and phosphorus oxide in stoichiometric relations. Crystallization kinetics was experimentally studied on powder samples with particle sizes ranging from 96 to 106 μm, 200 to 212 μm, and on bulk glassy samples using the non-isothermal differential scanning calorimetry. The evaluation of the measured data was performed using the Johnson–Mehl–Avrami, Matusita and Augis–Bennett models, and the y(α) and z(α) functions. In the case of the powder samples, the model analysis of the measured data showed that the crystallization mechanism was primarily performed through volume nucleation followed by 2D and 3D growth and in the bulk one by the surface and volume nucleation with 1D growth. Obtained kinetic parameters were used for reconstruction of the crystallization peaks using various models and compared with actual experimental data.

Magneto-optical properties of terbium-doped metaphosphate and borate glasses

The paper shows the results of Faraday Effect study of borate and metaphosphate glasses doped with various concentrations of terbium under uniform longitudinal magnetic field. The Verdet constant of glass under study is obtained based on the experimental data for several wavelengths. The optical and spectral properties of glasses are also studied.

The influence of phosphorus substitution by molybdenum on the chemical composition and certain properties of the zinc metaphosphate glass

xMoO3-50ZnO-(50-x)P2O5, i.e. (1-x/50)Zn(PO3)2-(x/50)ZnMoO4, glasses were prepared up to x = 25. It has been proved that the glasses are not a mixture of boundary components, but that chemical reactions taking place in the melt during synthesis produce in equilibrium a more complicated chemical mixture. Molybdenum is incorporated into the glass structure as a molybdate(2-) and also as complex cations, a colorless molybdenyl MoO4+ (d0 system) and blue colored MoO3+ (d1). The chemical model of the studied glasses was designed indicating that the glassy matrix gradually changes with increasing molybdenum content from pure anionic metaphosphate to the cationic-anionic network with the help of molybdenyl cation strongly bonded by four covalent donor-acceptor bonds with non-bonding phosphate oxygens. The compositional dependencies of some physical properties agree with the proposed chemical model. The melts or glasses of chemical compositions near the glass-forming border are less stable and immiscibility of glass phases was found.

Correlation Between Ionic Mobility and Plastic Flow Events in NaPO3-NaCl-Na2SO4 Glasses

We report on the evolution of the mechanical and electrical properties of sodium metaphosphate glasses with addition of sodium sulfate or sodium chloride. The addition of these two sodium salts converts the medium-range order of our glasses from 2D phosphate chains to a mixed 1D + 2D network similar to ionic glasses, while the short-range order of the phosphate units remains unaffected. Replacing the phosphate units by chloride ion monotonically decreases the glass transition temperature, but enhances the Young’s modulus and moderately increases the ionic conductivity. On the other hand, the sulfate group decreases the glass transition temperature as well, though the Young’s modulus remains constant, while the ionic conductivity strongly increases. The changes in conductivity are related to the enhancement of the ionic mobility in these glasses, which in turn affect the size and distribution of the plastic events taking place during indentation-driven deformation.

The effect of silica additive on the structural and luminescence properties of Eu3+/Tb3+ co-doped metaphosphate glasses

In this paper, we investigate the effect of silica additive on the structural and luminescence properties of Eu3+ and Eu3+/Tb3+co-doped sodium-calcium phosphate glasses. Eu3+ doped phosphate glasses have been prepared using melt-quenching technique and characterized through X-ray diffraction (XRD), differential thermal analysis (DTA), Fourier Transform Infrared (FTIR), Raman spectroscopy, ultraviolet–visible (UV–Vis) and luminescence measurements at room temperature. The incorporation of SiO2 led to an increase of glass transition temperature (Tg), indicating an improvement of glass network rigidity. This result was correlated with FTIR and Raman investigations which revealed the occurrence of more hydration-resistant POSi bonds. An intense red luminescence has been observed due to 5D0 → 7F2 transition of Eu3+ ions in these glasses. The luminescence spectra for Eu3+/Tb3+ co-doped phosphate glasses were then recorded with various Eu3+:Tb3+ molar ratio. Dependence of luminescence lifetimes on the increase of Eu3+: Tb3+ molar ratio was investigated. It was observed that the energy transfer process occurs from Tb3+ to Eu3+ in the studied glasses. Our results show that a tuneable color is achieved when Eu3+: Tb3+ molar ratio changed. The variation of the excitation wavelength can also tune the luminescence spectra of the new phosphate glasses.

Dynamics of proton infiltration into binary MO·P2O5 (M = Ca, Sr) phosphate glasses

Proton concentration of simple binary metaphosphate glasses under a pseudo fuel cell anode reaction was investigated at 350 °C by utilizing an in-situ Fourier transform infrared (FTIR) spectroscopy. Proton concentrations of both MO·P2O5 (M = Ca, Sr) glasses increase under humidified hydrogen atmosphere and applying a direct current voltage between platinum electrodes, suggesting that a proton infiltration occurs into these glasses. Compared with CaO·P2O5 glass, SrO·P2O5 glass shows higher proton concentration at the same period of time. Structure of glass network was investigated using synchrotron radiation X-ray diffraction, 31P magic-angle spinning nuclear magnetic resonance (MAS NMR) and FTIR (KBr method) spectroscopies. Strength of the cross-linking between phosphate chains via M2+ metal cations is correlated for the proton infiltration into phosphate glasses.

Magneto-optical properties of metaphosphate and borate glasses

The paper shows results of Faraday Effect study of potassium-alumina-borate and metaphosphate glass under uniform longitudinal magnetic field. The Verde constant of glass under study is obtained based on the experimental data for several wavelengths. Magneto-optical properties of two types of glass: K2O-Al2O3-B2O3 glass doped with MnFe2O4 nanocrystals and P2O2-Tb2O3-Ga2O3 glass are compared with industrial glass. Application prospects of borate and metaphosphate glass in fields of isolation of laser radiation, current and magnetic field sensing is shown.

Erasable and rewritable laser-induced gratings on silver phosphate glass

We herein report on the fabrication of high regularity, erasable and rewritable periodic surface patterns on silver metaphosphate glass (AgPO3) by means of ultrashort pulsed laser processing. The laser-induced periodic surface structures (LIPSS) are formed perpendicular to the laser beam polarization, exhibiting a periodicity similar to the laser wavelength. Notably, the so-formed periodic patterns can be readily erased upon further exposure to femtosecond laser irradiation under controlled conditions. This all-laser inscription and deletion protocol allows the reversible patterning of the phosphate glass surface by employing a single laser beam. Optical and Raman spectroscopy revealed that the formation of the periodic patterns and the erasing process do not cause any phosphate network modifications or structural damage on the glass, and thus, proving that the demonstrated reversible LIPSS process is entirely non-ablative. This remarkable feature could enable infinite cycles of the write/erase/re-write process on the same area of the glassy material, posing the AgPO3 glass as an important candidate for waveguides and optical responsive memory components of advanced photonic applications.

The glass-forming ability explained from local structural differences by NMR between glasses and crystals in alkali metaphosphates

The glass forming ability of inorganic substances has traditionally been evaluated in kinetic terms related to the rate of spontaneous crystallization of their melts, which is related to viscosity from the macroscopic point of view. However, differences or similarities between the local structures of glasses and crystals of the same composition could have an additional influence on the kinetic ability to form a stable glass or a crystal from a melt. In this work, the local structure of alkali metaphosphate glasses and crystals has been analyzed by means of 31P MAS-NMR to demonstrate that the ability to form a glass is directly related to the differences between the atomic organization in the glassy states and the structure of the stable crystals at lower temperatures. This implies that chemical compositions having a similar atomic order in their glass and crystal structures will not easily develop the disordered long-range structure of glass.

Synergistic thermo‐Raman and calorimetric kinetic study of the cation modifier's role in binary metaphosphate glasses

AbstractA comprehensive temperature‐dependent Raman spectroscopy and differential scanning calorimetry study has been performed on three metaphosphate glasses with different modifying cations (Ca2+, Ba2+, and Pb2+). The P–NBO (nonbridging oxygen) Raman spectral feature, the force constant, and the glass transition activation energy (AETg) are shown to be strongly correlated to the relative effective nuclear charge difference between the modifying and the glass former cations, ζ. In addition, the estimated AETg values between 3.6(2) and 4.7(2) eV are found to be in the range of the P–O bond energy values in the phosphate glasses. The study contributes to the enrichment of the bond exchange kinetic theory of the glass transition in general and to the bond modifying mechanism of the cations. The authors propose that Raman spectroscopy alone can be implemented reliably for evaluation not only of AETg, but for calculation of the Morse potential of the moiety crucial for the onset of glass transition. Alternatively, in glasses without Raman scattering, the force constant of the critical moiety can be deduced from calorimetric measurements alone. The proposed analytical methodology broadens Raman spectroscopy and calorimetric applications and offers a viable technique for all types of glass matrices.

Using EXAFS data to improve atomistic structural models of glasses.

Quantitative characterization of the atomic structure of multi-component glasses is a long-standing scientific challenge. This is because in most cases no single experimental technique is capable of completely resolving all aspects of a disordered system's structure. In this situation, the most practical solution for the materials scientist is to apply multiple experimental probes offering differing degrees of insight into a material's properties. This powerful and widely adopted approach does, however, transfer the characterization challenge to the task of developing a coherent data analysis framework that can appropriately combine the diverse experimental insight into a single, data-consistent, structural model. Here, taking a terbium metaphosphate glass as an example system, it is illustrated how this can be achieved for X-ray diffraction and extended X-ray absorption fine-structure (EXAFS) spectroscopy data, using an empirical potential structure refinement approach. This methodology is based on performing a Monte Carlo simulation of the structure of a disordered material that is guided to a solution consistent with the provided experimental data, by a series of pairwise perturbation potentials operating on a classical reference potential foundation. For multi-component glasses the incorporation of EXAFS data into the resulting bulk structural models is shown to make a critical contribution that is required to properly account for the increase in local structural order that can develop in the melt-quench process of glass formation.

Spectroscopic Properties of Yb3+/Nd3+ Co-doped Ions in SiO2-Al2O3-Na2CO3-SrF2-CaF2 Oxyfluoride Glasses for Photonic Applications

The Yb3+ and Yb3+/Nd3+ co-doped SiO2-Al2O3-Na2CO3-SrF2-CaF2 oxyfluorosilicate glasses have been prepared by high temperature melt-quenching method. The prepared glasses are excited with 808 nm, and the near infrared emission bands are observed. The intensified emission band was centered at 1030 nm (2F5/2 -> 2F7/2) of Yb3+ ions. Stimulated emission cross-section was evaluated for the prominent 2F5/2 -> 2F7/2 transition of Yb3+ ion by using the Mc-Cumber theory. The energy transfer from Nd3+ to Yb3+ ions in co-doped silicate based oxyfluoride glasses are described under the 514 nm excitation wavelength. Full Text: PDF ReferencesN. Chiodini, A. Paleari, G. Brambilla, E. R. Taylor, "Erbium doped nanostructured tin?silicate glass?ceramic composites", Appl. Phys. Lett. 80, 4449 (2002). CrossRef D. Jaque, J. Capmany, F. Molero, Z. D. Luo, J. G. Sole, "Up-conversion luminescence in the Nd3+:YAB self frequency doubling laser crystal", Opt. mater. 10, 211 (1998). CrossRef H. Lin, G. Meredith, S. Jiang, X. Peng, T. Luo, N. Peyghambarian, E. Yue-Bun Pun, "Optical transitions and visible upconversion in Er3+ doped niobic tellurite glass", J. Appl. Phys. 93, 186 (2003) CrossRef Atul D. Sontakke, K. Annapurna, "Phonon assisted effective non-resonant energy transfer based 1 ?m luminescence from Nd3+?Yb3+ codoped zinc?boro?bismuthate glasses", J. Lumin. 138, 229 (2013). CrossRef F. Liegard, J.L. Doualan, R. Moncorge, M. Bettinelli, "Nd3+ ? Yb3+ energy transfer in a codoped metaphosphate glass as a model for Yb3+ laser operation around 980 nm", Appl. Phys. B 80, 985 (2005) CrossRef A. Miguel, B. Fan, R. Balda, X. Zhang, J. Fernandez, J.L. Adam, "Spectroscopy and energy transfer in Nd3 +/Yb3 + codoped chalcohalide glasses", J. Non-Cryst. Solids 377, 110 (2013). CrossRef G. Devarajulu, B. Deva Prasad Raju, "Effect of concentration variation on 2.0 ?m emission of Ho3+-doped SiO2?Al2O3?Na2CO3?SrF2?CaF2 oxyfluorosilicate glasses", App. Phy. A, 124 (2018). CrossRef Radoslaw Lisiecki, Elzbiecta Augustyn, Witold Ryba-Romanowski, Michal Zelechower, "Er-doped and Er, Yb co-doped oxyfluoride glasses and glass?ceramics, structural and optical properties", Opt. Mater. 33, 1630 (2011). CrossRef G. Chen, Q. Zhang, G. Yang, and Z. Jiang, "Mid-Infrared Emission Characteristic and Energy Transfer of Ho3+-Doped Tellurite Glass Sensitized by Tm3+", J. Fluoresc. 17, 301 (2007). CrossRef D. E. McCumber, "Theory of Phonon-Terminated Optical Masers", Phys. Rev. 134, 299 (1964). CrossRef D.L. Deloach, S.A. Payne, L.K. Smith, W.L. Kway, W. F. Krupke, "Laser and spectroscopic properties of Sr5(PO4)3F:Yb", J. Opt. Soc. Am. B 11, 269 (1994). CrossRef K. Venkata Krishnaiah, R. Rajeswari, K. UpendraKumar, S. Surendra Babu, I.R. Martin, C.K. Jayasankar, "Spectroscopy and radiation trapping of Yb3+ ions in lead phosphate glasses", J.Quant. Spect. Rad. Trans. 140, 37 (2014). CrossRef

Electrical conductivity and viscosity of phosphate glasses and melts

Phosphate glasses are of great interest for basic research and for special applications in various fields as technical and optical glasses. Metaphosphate compositions with PO4-chain structure are mostly used. The cations have a significant effect on the properties of the glasses and melts. This was studied in more details. High purity metaphosphate glasses, Mn(PO3)n with M = Na+, K+, Zn2+, Mg2+, Ca2+, Sr2+, Ba2+, Al3+ and Fe3+, were prepared and the optical and thermal properties were measured with different methods. The electrical conductivity of glasses and melts is the property of great practical importance. It was determined by impedance spectroscopy in a wide temperature range from 300 to 1250 °C in frequency range of 0.1 Hz to 6 MHz. The electrical conductivity of alkaline earth phosphate glasses and melts increases with increasing ion radius of the cation. NaPO3 and KPO3 glasses and melts have much higher conductivity. Viscosity measurements were carried out from transformation temperature, Tg, to the melt. The measured data were fitted and the activation energies of the conductivity and viscosity were calculated. Simple exponential behavior was found at temperatures below Tg, but above Tg only in very narrow temperature range. The relation between conductivity and viscosity was considered.

Development of string-shaped radiophotoluminescence dosimeter for high-radiation field

We developed a long and bendable string-shaped dosimeter, 2 mm in diameter. This string-shaped dosimeter, which was made from a mixture of silver-activated metaphosphate glass particles and polylactic acid resin, was fabricated with a filament extruder. The maximum ratio of glass to resin by weight was 20%. The photoluminescence spectra had absorbed-dose-dependent peaks at 635 nm. At doses above 50 Gy, orange photoluminescence could be observed with the naked eye. A one-dimensional (1-D) readout system for string-shaped dosimeters comprised an ultraviolet (UV)-LED, a photodiode, and a drawing machine. In a preliminary experiment, a string-shaped dosimeter was uniformly exposed to 60Co gamma rays. The position dependency of the detection efficiency of the string-shaped dosimeter was investigated, and its coefficient of deviation was approximately 4%. The string-shaped dosimeter was partly exposed to X-ray beams. The 1-D dose profile of the string-shaped dosimeter was successfully obtained by the readout system. The radiophotoluminescence response was sufficiently related with the absorbed dose in a dose range up to 500 Gy. The spatial resolving power (FWHM) was approximately 3 mm, owing to the width of the slit for the UV illuminator in the readout system. These results indicated that the string-shaped dosimeter was useful in 1-D dose measurement of the high-radiation field.

Structure properties relationship in calcium sodium metaphosphate and polyphosphate glasses

Two series of glasses, the first with the formula (50-x/2)Na2O-xCaO-(50-x/2)P2O5 and an oxygen over phosphorus O/P ratio between 3 and 3.33 and the second with the composition (50-x)Na2O-xCaO-50P2O5 with an O/P = 3, were obtained by melt quenching and studied in order to understand the effects of the CaO addition on the structure, physical properties and thermochemistry of polyphosphate and metaphosphate glasses. The spectroscopic investigations by Fourier Transform Infrared spectroscopy and 31P Magic Angle Spinning Nuclear Magnetic Resonance indicate in the first series, the shortening of the polyphosphate chains as CaO content increases. The spectra of the second series indicate the conservation of the metaphosphate chains. The density and thermal analysis measurement show the shrinking and the reticulation of the phosphate network as CaO is added in both series and the chemical durability of the glasses is enhanced by the substitution of the PONa and POP bonds by the POCa– bonds. The thermochemical study shows the decrease of the dissolution heat of the glasses when the average chain length decreases and when the chemical durability of the glass increases. The molar enthalpy of mixing indicates the presence of two ranges of interaction in the metaphosphate compositions around 0–20% and 25–50% of CaO.

Mixed-modifier effect in alkaline earth metaphosphate glasses

Modifier-mixing provides a useful tool for tailoring the structural dynamics of oxide glasses. Its physical basis, however, remains subject to intense discussion. Here, we extend our previous consideration of Ca-Mg mixing in alkaline earth metaphosphate glasses [J. Non-Cryst. Solids 468, 74–81 (2017)] across the broader range of alkaline earth species. We report on the effects of divalent modifier mixing for pairs selected from the group of Mg, Ca, Sr and Ba. For this, short-range structural features as obtained from nuclear magnetic resonance, Raman and far-infrared spectroscopy are related to various physical properties, including ionic mobility. Depending primarily on the difference in ion size and bond localization among the modifier cation species, we find different extents of the mixed-modifier effect. This agrees with the dynamic structure model in which the mismatch of cation sites governs non-linear mixing effects.

Permanent structural anisotropy in a hybrid fiber optical waveguide

The shearing of a liquid with a one-dimensional molecular structure causes structural anisotropy through chain orientation. Here, we exploit this behavior to generate a hybrid fiber optical waveguide with tailored transversal anisotropy. Preferentially oriented chains of silver metaphosphate glass are obtained by pressure-assisted melt filling of silica micro-capillaries at several filling temperatures, pressures, internal capillary diameters, and filling times. Accurate control of the aforementioned parameters enables the adjustment of the degree of anisotropy within limits. Annealing of the waveguides induces volume shrinkage, which is taken as further evidence for the alignment of phosphate chains. These are the first steps towards a novel paradigm for producing glass-based fiber waveguides in which the transversal anisotropy is used to alter optical functionality.

The structure and basic properties of iron zinc metaphosphate glasses

The structure and basic properties of iron zinc metaphosphate glasses

Reducing Power of Phosphate Matrix in Binary Barium Phosphate Glasses Doped with 3d Transition Metals and Effects of Gamma Radiation

Spectroscopic characterization was performed for base and first row transition metal ions (3d TM) doped barium metaphosphate glasses. The procedure was conducted using FTIR and optical spectral measurements before and after 8 M rad gamma irradiation. Electronic spectra show distinct UV absorption with a peak around 230 nm in nearly all samples correlated with trace iron ions present as an impurity within the chemicals used for the preparation of the glasses. 3d TM ions-doped samples exhibit additional characteristic bands mainly in the visible due to each respective TM ion. Such optical spectra indicate and support the assumption that the host phosphate glass generally promotes the reduced state or octahedral coordination of the TM ions to a measurable extent. Gamma irradiation produces mostly an extension of the UV spectra and this effect is correlated with the assumption of photochemical reactions of the trace iron ions impurities during the irradiation process in which some ferrous ions capture positive holes and are transformed to additional ferric ions causing the extension. FTIR absorption spectra reveal vibrational bands due mainly to metaphosphate groups and the P-O-P mode while TM ions doped glasses show no distinct variations due to the stability of the phosphate network containing high content of heavy Ba2+ ions and the presence of TM ions in low doping percent.