Sol–gel synthesis of erbium-doped yttrium silicate glass–ceramics

Ranganathan, Varadharajan; Klein, Lisa C.

doi:10.1016/j.jnoncrysol.2008.03.033

Cited by 21 publications

(10 citation statements)

References 25 publications

(28 reference statements)

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“…Based on the prior work with hydrated rare‐earth nitrates, 39–41 the weight loss at 50°–250°C was attributed to evaporation of freely adsorbed water and water of hydration. Similar water weight losses have been observed for disilicate powders formed with hydrated rare‐earth precursors 24,26,27,36 …”

Section: Resultssupporting

confidence: 78%

“…Weight loss at 50°–250°C was attributed to evaporation of freely adsorbed water. Similar water weight losses were observed for SiO 2 /Ho(OH) 3 precursor and disilicate powders formed with hydrated rare‐earth precursors 24,26,27,36 …”

Section: Resultssupporting

confidence: 76%

“…The rare‐earth disilicates are commonly prepared by a variety of methods, which include conventional solid‐state reaction of mixed oxides Re 2 O 3 and SiO 2 , calcinations of rare‐earth disilicate sol–gel precursors, and hydrothermal processing 9,24–30 . An attempt to make the γ‐phase by calcining SiO 2 and Y 2 O 3 powders to temperatures as high as 1600°C was not successful 31 .…”

Section: Introductionmentioning

confidence: 99%

“…23 The rare-earth disilicates are commonly prepared by a variety of methods, which include conventional solid-state reaction of mixed oxides Re 2 O 3 and SiO 2 , calcinations of rare-earth disilicate sol-gel precursors, and hydrothermal processing. 9,[24][25][26][27][28][29][30] An attempt to make the g-phase by calcining SiO 2 and Y 2 O 3 powders to temperatures as high as 16001C was not successful. 31 Sol-gel nanoparticle precursors have been used to synthesize aand d-Y 2 Si 2 O 7 , but similar work on the synthesis of g-phase has not been reported.…”

Section: Introductionmentioning

confidence: 99%

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Rare-Earth Disilicates As Oxidation-Resistant Fiber Coatings for Silicon Carbide Ceramic-Matrix Composites

Boakye

Mogilevsky

Hay

et al. 2011

Journal of the American Ceramic Society

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Current SiC‐based ceramic–matrix composites (SiC–SiC CMCs) rely on carbon or boron nitride fiber–matrix interphases for toughness and flaw tolerance. However, oxidation of these interphases can be performance limiting in many CMC applications. The γ‐polymorph of the rare‐earth disilicates (RE2Si2O7) is a potential oxidation‐resistant alternative to carbon or BN. The formation of γ‐Y2Si2O7 and γ‐Ho2Si2O7 at different temperatures and processing environments was investigated. Silica–yttrium hydroxide and silica–holmium hydroxide dispersions were made and heat treated at 1200°–1400°C for 8 h in air and argon. LiNO3 was added to the dispersions to enhance the formation of γ‐Y2Si2O7 and γ‐Ho2Si2O7. The effects of excess silica and LiNO3 dopant on the formation of γ‐Y2Si2O7 were investigated. Coatings of Y2Si2O7 and Ho2Si2O7 were made on α‐SiC plate and SCS–0 SiC fiber using these dispersions. These were heat treated in argon and argon—500 ppm oxygen mixtures at 1400°C/8 h. For coatings heat treated in argon—500 ppm oxygen mixtures, X‐ray diffraction showed the formation of single phase γ‐Ho2Si2O7 and a mixture of γ and β‐Y2Si2O7 at 1400°C. Scanning electron microscopic image analysis gave an estimate of 18 vol% of excess silica for γ‐Y2Si2O7 formed with high Si:Y ratio and ∼5 vol% excess silica for material formed with lower Si:Y ratio. Transmission electron microscopy of samples directly beneath indentations showed both extensive dislocation slip and fracture.

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Section: Resultssupporting

confidence: 78%

Section: Resultssupporting

confidence: 76%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Rare-Earth Disilicates As Oxidation-Resistant Fiber Coatings for Silicon Carbide Ceramic-Matrix Composites

Boakye

Mogilevsky

Hay

et al. 2011

Journal of the American Ceramic Society

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“…These doped glasses, possibly containing dopant nanoclusters, are as vital to the future development of photonic systems as integrated circuits are to the electronic systems. Number of techniques have been employed to achieve an in-depth and homogeneous diffusion, but all come with some limitations and constraints [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

A novel technique for doping silicate glasses with transition metals and rare-earth for waveguides applications

Ali

Gonella

Cattaruzza

et al. 2010

International Conference on Photonics 2010

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Field-Assisted Solid-State Ion-Exchange (FASSIE) technique for doping silicate glasses with either transition metals or rare earths has been attracting much attention for its potential application in light waveguides, luminescent materials and for the possibility to realize systems in which formation of metal nanoclusters is controlled by suitable post-exchange techniques. In this framework, metallic films of either silver or gold are deposited onto soda-lime and borosilicate glasses by the rf-sputtering technique. Owing to an external electric field,\ud metal ions diffuse into the glass replacing its alkali content\ud at different values of processing temperature and electric\ud field. The nanocomposites are then characterized by\ud secondary ion mass and m-line spectrometries, optical\ud absorption and transmission electron microscopy, indicating\ud that the migration not only depends on the experimental\ud conditions but also on the matrix and the chemical\ud phenomena occurring at the metal/glass interface. For both\ud transition metals, dark m-lines detection suggests that the\ud samples may actually support guided modes, although the\ud quality of the surface creates some problems for the prism\ud coupling used in the measurements. In particular, the yet\ud broaden lines seem to indicate two modes in the visible and\ud one in the IR

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