scholarly journals Spectroscopic and Surface Crystallization Characterizations of Yttrium-Doped Phosphate Glasses

Crystals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 109
Author(s):  
Haijian Li ◽  
Hao Zou ◽  
Zhihua Sun ◽  
Yi Xu ◽  
Changjian Wang ◽  
...  

The composition, structure, and thermal behaviors of yttrium-containing phosphate glasses were studied in this work, and the glass-ceramics were prepared via the two-step crystallization method. The XRD and SEM-EDS results show the forming range of the phosphate glass system and the formation of YPO4 (xenotime) due to the addition of excessive Y2O3. The spectroscopic characterization of these glasses presented shifts of the infrared and Raman bands, demonstrating the depolymerization of the glass network and the formation of novel P–O–Y bonds, and the deconvoluted Raman spectra also exhibited the occurrence of the disproportionation reaction in the glass melting process. The content of non-bridging oxygen (NBOs) from the UV–vis spectra first increased and then decreased with increasing Y2O3. The thermal behaviors show that the Y2O3 reduced the crystallization peak temperature and the thermal stability of the glasses. The crystalline behaviors of the phosphate glass matrix were investigated at different crystallization times of 2–10 h, and a transformation of the crystallization mechanism from surface to volume crystallization was found. The yttrium phosphate glass-ceramics crystallized for 10 h exhibited transformation of the main crystalline phases with increasing Y2O3, and the grain-oriented crystalline surface became irregular.

2013 ◽  
Vol 587 ◽  
pp. 128-131 ◽  
Author(s):  
Daniel Navarro da Rocha ◽  
Leila Rosa de Oliveira Cruz ◽  
João Luiz do Prado Neto ◽  
Nadia Mohammed Elmassalami Ayad ◽  
Luciano de Andrade Gobbo ◽  
...  

The present study concerns the production and characterization of porous hydroxyapatite/niobo-phosphate glass ceramics to be used for bone repair. The scaffolds were produced by hydrothermal deposition of monetite on polyurethane sponge substrates, further converted to hydroxyapatite in an alkali solution. After heat treatment, elimination of the organic sponge provides a three-dimensional (3D) structure. Niobo-phosphate glasses were added to the heat treated struts and the scaffolds were sintered. The porous bodies were characterized by field-emission gun scanning electron microscope (FEG-SEM) with energy-dispersive X-ray spectroscopy (EDS).


Author(s):  
Hidekazu Kobayashi ◽  
Ippei Amamoto ◽  
Takuma Yokozawa ◽  
Teruo Yamashita ◽  
Takayuki Nagai ◽  
...  

As the part of investigation for immobilization of the sludge as one of the radioactive wastes arising from the treatment of contaminated water at Fukushima Dai-ichi nuclear power plant, applicability of vitrification method has been evaluated as a candidate technique. The aim of this study is to evaluate the influence of NaCl as one of the main constituents of sludge, on glass formation and glass properties. Two kinds of iron phosphate glass (IPG) media in the xFe2O3-(100-x)P2O5, with x = 30 and 35 (mol%) were chosen and the glass formation, structure and properties including density, coefficient of thermal expansion, glass transition temperature, onset crystallization temperature and chemical durability of NaCl-loaded IPG were studied. The results are summarized as follows. Sodium chloride, NaCl could be loaded into IPG medium as Na2O and Cl contents and their loading ratio could be up to 19 and 15 mol%, respectively. Majority of Cl content of raw material NaCl was thought to be volatilized during glass melting. Loading NaCl into IPG induces to depolymerize glass network of phosphate chains, leads to decrease both glass transition and onset crystallization temperatures, and to increase coefficient of thermal expansion. NaCl-loaded IPG indicated good chemical durability in case of using 35Fe2O3-65P2O5 medium.


2008 ◽  
Vol 1124 ◽  
Author(s):  
Melody Lyn Carter ◽  
Hui Li ◽  
Yingjie Zhang ◽  
Andrew L Gillen ◽  
Eric R Vance

AbstractHot isostatically pressed (HIPed) glass-ceramics for the immobilization of uranium-rich intermediate-level wastes and Hanford K-basin sludges were designed. These were based on pyrochlore-structured Ca(1-x)U(1+y)Ti2O7 in glass, together with minor crystalline phases. Detailed microstructural, diffraction and spectroscopic characterization of selected glass-ceramic samples has been performed, and chemical durability is adequate, as measured by both MCC-1 and PCT-B leach tests.


2020 ◽  
Vol 142 (1) ◽  
pp. 203-209 ◽  
Author(s):  
Paweł Goj ◽  
Małgorzata Ciecińska ◽  
Magdalena Szumera ◽  
Paweł Stoch

Abstract Iron phosphate glasses are materials that can have many applications like durable matrixes in waste immobilization techniques, biomaterials, optoelectronic devices, etc. Their possible usage is related to their glass network and thermal properties. The influence of Na2O content on thermal properties and crystallization ability of iron phosphate glass of base composition 30 Fe2O3–70 P2O5 mol% were studied. Increasing the content of Na2O causes a decrease in transformation temperature and increase in ΔCp. Characteristic temperatures, thermal stability and crystallizing phases were determined. Increasing content of sodium causes depolarization of iron phosphate glass network which causes a continuous change in ΔCp and glass transformation temperature. Discontinuous change in some glass properties suggests structure rebuilding about 30 mol% of Na2O.


2006 ◽  
Vol 932 ◽  
Author(s):  
Paul A. Bingham ◽  
Russell J. Hand ◽  
Charlie R. Scales

ABSTRACTVitrification is a potential route for the immobilisation of Plutonium Contaminated Material (PCM). This is an Intermediate Level Waste (ILW) arising from operations in which there is contact with Pu isotopes. PCM consists of low levels of Pu combined with metals, masonry, glass, ceramics, polymers and other carbonaceous materials. Simulated PCM containing CeO2 as a PuO2 surrogate was mixed with a phosphate precursor and vitrified. Pre-oxidation of PCM simulant prior to vitrification minimised the violence of batch reactions. No pre-oxidation produced inhomogeneous slag-like materials with high residual metals and particulates. Pre-oxidation at 600°C in air and at 1200°C in an O2-rich atmosphere produced more favourable results, with increasingly vitreous products resulting from more oxidised PCM simulant. The most oxidised PCM simulant produced phosphate glasses with low levels of particulate inclusions, as confirmed by x-ray diffraction and scanning electron microscopy. Particulates included iron-rich metallics and aluminous oxides. Increased melting times and temperatures may have reduced the number of inclusions slightly, but O2 bubbling during melting resulted in little additional benefit. Waste loading equivalent to ∼60 weight % of untreated waste may be possible. There was little evidence of Ce partitioning, indicating that it was immobilised within the glass matrix and had little preference for metallic or crystalline phases. These results demonstrate the potential feasibility for vitrification of PCM in phosphate glass, justifying further investigation into this potentially novel solution.


RSC Advances ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 1822-1830
Author(s):  
Martin Mangstl ◽  
Jan Konrad Wied ◽  
Johannes Weber ◽  
Christian Pritzel ◽  
Reinhard Trettin ◽  
...  

The novel glass shows the lowest glass transition temperature known for binary phosphate glass systems without acidic protons.


2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
Gerardo Cristian Scarpignato ◽  
Daniel Milanese ◽  
Joris Lousteau ◽  
Nadia Giovanna Boetti ◽  
Emanuele Mura

We present the fabrication and characterization of a short core pumped fiber amplifier made of Yb3+-Er3+codoped phosphate glasses. The 27 mm long amplifier provides a maximum internal gain of 10.7 dB for a signal of −30 dBm at 1535 nm with a 479 mW pump power operating at 975.6 nm. This leads to a gain of 4.0 dB/cm, which compares favorably to other recent works.


2007 ◽  
Vol 555 ◽  
pp. 377-381
Author(s):  
R. Krsmanović ◽  
Giovanni Bertoni ◽  
Gustaaf Van Tendeloo

Samples of transparent glass-ceramics in the ternary system Li2O-Al2O3-SiO2 (LAS), with Er2O3 as a luminescent dopant, are investigated. The initial glass is obtained by the classical melting technique. In order to induce ceramization of the glass, TiO2 and ZrO2 are added in small amount as nucleating agents. The thermal treatments at 730 and 770°C are carried out to promote formation of titanium zirconate solid solution precipitates. The spatial distribution of the precipitates in the material, their morphology, and their composition are investigated with TEM, HRTEM, HAADF-STEM, EELS and EFTEM. The results demonstrate that with the glass-melting preparation technique it is possible to achieve small nanoparticles with uniform distribution and higher number density than with the sol-gel glass preparation.


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