An Exafs Study of Compositional Homogeneity in Sol-gel Processed Potassium Tantalum Niobates

1998 ◽  
Vol 524 ◽  
Author(s):  
A. P. Wilkinson ◽  
J. XU ◽  
S. Pattanaik
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Sol Gel ◽  
Direct Reaction ◽  
Sol Gel Process ◽  
Compositional Homogeneity ◽  
Exafs Study ◽  
Sol Gel Synthesis

ABSTRACTA series of K(Ta1-x Nbx)O3 solid-solution samples were prepared by direct reaction of oxides and carbonates, a homogeneous sol-gel process, and an inhomogeneous sol-gel process. The inhomogeneous sol-gel samples were prepared by the prehydrolysis of separate KTaO3 and KNbO3 precursor solutions followed by mixing of the resulting sols, drying and calcination. An examination of these samples by EXAFS at the Ta LIII and Nb K-edges, i) illustrated the difficulty of obtaining homogeneous solid solutions via direct reaction of oxides/carbonates, and ii) showed that the homogeneity of a solid-solution could be controlled by varying the hydrolysis procedure used during its sol-gel synthesis.

scholarly journals EXAFS study of the Fex/ZrO2composite nanomaterials obtained by sol–gel synthesis

2001 ◽  
Vol 8 (2) ◽  
pp. 528-530 ◽  
Author(s):  
Vladimir Kriventsov ◽  
Dmitrii Kochubey ◽  
Jose Antonio Navio ◽  
Maria Carmen Hidalgo ◽  
Gerardo Colón ◽  
...  
Keyword(s):  
Sol Gel ◽  
Exafs Study ◽  
Sol Gel Synthesis

scholarly journals FABRICATION AND PROPERTIES OF Co DOPED Bi0.5K0.5TiO3 – BiFeO3 SOLID SOLUTION

2018 ◽  
Vol 56 (1A) ◽  
pp. 197
Author(s):  
Nguyen Hoang Tuan
Keyword(s):  
Solid Solution ◽  
Raman Spectroscopy ◽  
Magnetic Properties ◽  
Crystal Structures ◽  
Solid Solutions ◽  
Sol Gel ◽  
Structure And Properties ◽  
Antiferromagnetic Ordering ◽  
Co Doped ◽  
Good Agreement

In this study, we present some results on the structure and properties of the solid solution of Bi0.5K0.5TiO3– BiFeCoO3 (BKT – BFCO) by Sol-gel method. Crystal structures of BKT – BFCO solid solutions were studies by XRD and Raman spectroscopy. The results were in good agreement with the previous reports of Bi0.5K0.5TiO3– BiFeO3 (BKT – BFO) and Bi0.5K0.5TiO3 – BiCoO3 (BKT – BCO) solid solutions. The magnetic properties were investigated via unsaturated M-H loop, which showed the competition of paramagnetic and antiferromagnetic ordering in BKT – BFCO. However, differing from the BKT – BFO and BKT – BCO solid solutions, the unclear values of saturated magnetism in BKT – BFCO raised the unexplained question, which needed further studies.

Synthesis and Oxygen Sensing Properties of Ti1-xSnxO2 Solid Solutions Nanoparticles

2013 ◽  
Vol 575-576 ◽  
pp. 45-49
Author(s):  
Ai Qing Wu ◽  
Xin Zuo Fang ◽  
Xin Hua Lin ◽  
Huan Qin Wang ◽  
Ying Xian Wang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Solid Solutions ◽  
Sol Gel ◽  
Hydrothermal Process ◽  
Typical Sample ◽  
Sol Gel Process ◽  
Crystallite Sizes ◽  
Hybrid Alkoxides ◽  
Xrd And Tem ◽  
High Temperature Calcination

Rutile Ti1xSnxO2(0.2x<1) solid solutions had been prepared using a sol-hydrothermal method, which combined the conventional sol-gel process with hydrothermal method. Hybrid alkoxides of Ti4+and Sn4+were used as precursors in the sol-gel process and Sn4+served as crystal-inducing agent during the formation of rutile crystal lattice in the hydrothermal process at 200°C. The microstructures and morphologies of nanoparticles were detected with XRD and TEM. Rutile Ti1xSnxO2solid solutions nanoparticles with well-distributed crystallite sizes about 10nm were obtained with Sn4+content above 20mol% without any high temperature calcination. The oxygen sensitivity properties of Ti1xSnxO2solid solutions had also been investigated. It is proved Ti1xSnxO2solid solutions exhibited higher oxygen responses than single TiO2or SnO2. A typical sample of Ti0.5Sn0.5O2presented the best sensitivity is approximately 6 under 400°C.

Reinspection of formation of BiFe1-xMnxO3 solid solutions via low temperature sol-gel synthesis route

2021 ◽  
Vol 111 ◽  
pp. 106458
Author(s):  
Ramunas Diliautas ◽  
Aldona Beganskiene ◽  
Dovydas Karoblis ◽  
Kestutis Mazeika ◽  
Dalis Baltrunas ◽  
...  
Keyword(s):  
Low Temperature ◽  
Solid Solutions ◽  
Sol Gel ◽  
Synthesis Route ◽  
Sol Gel Synthesis

Sol–gel synthesis and electrical properties of (ZrO2)0.85(REO1.5)0.15 (RE = Sc, Y) solid solutions

2001 ◽  
Vol 12 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Yawen Zhang ◽  
Yu Yang ◽  
Shujian Tian ◽  
Chunsheng Liao ◽  
Chunhua Yan
Keyword(s):  
Electrical Properties ◽  
Solid Solutions ◽  
Sol Gel ◽  
Sol Gel Synthesis

Effect of Sintering Time on the Phase Composition in PFN Ceramics Prepared by Sol-Gel Process

2009 ◽  
Vol 409 ◽  
pp. 317-321 ◽  
Author(s):  
Helena Bruncková ◽  
Ľubomír Medvecký ◽  
Ján Mihalik
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Pyrochlore Phase ◽  
Molar Ratio ◽  
Sintering Time ◽  
Sol Gel Process ◽  
Sol Gel Synthesis ◽  
Spherical Grains ◽  
Bimodal Grain Size ◽  
Iron Niobate

Lead iron niobate Pb(Fe0.5Nb0.5)O3 (PFN) ceramics were prepared using sol-gel synthesis by mixing acetates Pb and Fe with Nb-ethylene glycol-tartarate (Pechini) complex at 80°C, calcination of gels at 600°C and sintering at 1150°C for various times. The metastable pyrochlore phase Pb3Nb4O13 in stoichiometric precursor was partially decomposed to perovskite phase Pb(Fe0.5Nb0.5)O3 in ceramics sintered at temperature of 1150°C for 2, 4 and 6 hours. Excess of Pb in molar ratio (Pb:Fe:Nb = 1.2:0.5:0.5) caused the increase of the content of the perovskite phase (~50 vol.%) in nonstoichiometric PFN ceramics sintered at 1150°C for 6 hours while the decrease in perovskite phase content was found in stoichiometric PFN ceramics (~16 vol.%). In microstructures of PFN ceramics sintered at 1150°C for different times, the bimodal grain size distribution was observed with small spherical grains of perovskite phase and larger octahedral grains of pyrochlore phase. EDX analysis confirm that complex types of pyrochlore phases that differ in iron content were present in ceramics.

scholarly journals Formation of nanoscopic CaF2via a fluorolytic sol–gel process for antireflective coatings

2015 ◽  
Vol 3 (8) ◽  
pp. 1716-1723 ◽  
Author(s):  
Alexander Rehmer ◽  
Kerstin Scheurell ◽  
Erhard Kemnitz
Keyword(s):  
Sol Gel ◽  
Nano Particles ◽  
Antireflective Coatings ◽  
Sol Gel Process ◽  
Sol Gel Synthesis ◽  
First Time

For the first time transparent antireflective CaF2-coatings were prepared from clear CaF2-sols obtained via the fluorolytic sol–gel synthesis and containing homo-dispersed CaF2 nano-particles.

Sol-gel synthesis of biocompatible silica-chitosan hybrids and hydrophobic coatings

2008 ◽  
Vol 23 (8) ◽  
pp. 2053-2060 ◽  
Author(s):  
S. Smitha ◽  
P. Shajesh ◽  
P. Mukundan ◽  
K.G.K. Warrier
Keyword(s):  
Condensation Reaction ◽  
Sol Gel ◽  
Visible Region ◽  
Reaction Medium ◽  
Optical Transmittance ◽  
Hydrophobic Coatings ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Sol Gel Synthesis

A new organic–inorganic hybrid synthesized through a sol-gel process starting from alkoxysilane and chitosan is reported. Functionalization of the hybrid was effected through in situ hydrolysis–condensation reaction of methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) in the reaction medium. The process yields highly transparent and hydrophobic silica–chitosan hybrids. The hybrid gel was investigated with respect to chemical modification, thermal degradation, hydrophobicity, and transparency under the ultraviolet-visible region. The extent of hydrophobicity had been tailored by varying the precursor ratio. SiO2–chitosan–MTMS hybrids showed a higher thermal stability than SiO2–chitosan–VTMS (SCV) hybrids with respect to hydrophobicity. Condensation of silsesquioxanes generated from the hydrolysis of MTMS and VTMS over the silica-chitosan particles impart hydrophobicity to the hybrid. The coatings of functionalized SiO2–chitosan precursor sol on glass substrates showed nearly 100% optical transmittance in the visible region. The present hybrid material may find application in optics and other industries.

scholarly journals Synthesis, microstructure, mechanical properties and luminescence of a ceramics Gd(NbxTa1−x)O4

2020 ◽  
Vol 10 (01n02) ◽  
pp. 2060014
Author(s):  
O. B. Shcherbina ◽  
S. M. Masloboeva ◽  
N. I. Steblevskaya ◽  
M. V. Belobeletskaya ◽  
V. V. Efremov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Solid Solutions ◽  
Sol Gel ◽  
Luminescent Properties ◽  
Exciting Radiation ◽  
Small Addition ◽  
Mode I

Ceramic solid solutions GdNbx[Formula: see text]O4 ([Formula: see text]–1) were synthesized by sol–gel. Morphological particularities of microstructure were studied, strength characteristics (Young’s modulus) and stress intensity factor for mode I [Formula: see text] were evaluated. The latter is a criterion of crack resistance of the material. Luminescent properties of solid solutions GdNbx[Formula: see text]O4 were researched under UV exciting radiation. A comparatively small addition of Ta ([Formula: see text]) was shown to increase luminescence intensities of centers [Formula: see text]–O−. An addition of Ta to GdNbO4 leads to creation of solid solution [Formula: see text][Formula: see text]O4. Intensity of these centers is 3–6.5 times larger than that of GdNbO4 and GdTaO4.

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