Formation and characterization of nanocrystalline binary oxides of yttrium and rare earths metals

Kimmel, G.; Zabicky, Jacob; Goncharov, Elena; Mogilyanski, D.; Venkert, A.; Bruckental, Yishai; Yeshurun, Y.

doi:10.1016/j.jallcom.2005.12.037

Cited by 11 publications

(14 citation statements)

References 15 publications

(15 reference statements)

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“…In Ce 1 − x Lu x O 2 − x /2 − δ , the change of cell parameter with Lu content is slow and linear for x < ~0.35, but then the slope becomes steeper. This observation agrees well with dependence of the cell parameter on composition reported by Kimmel et al 2006 at similar temperature and time of heating (900 °C/3 h) for Y-doped ceria. The authors assigned the deviations from linearity to coalescence of oxygen vacancies, which grows up with increasing dopant content (Bae et al 2004).…”

Section: Resultssupporting

confidence: 92%

“…Chemical formula with undetermined “δ” factor was used, instead of stoichiometric Ce 1 − x Lu x O 2 − x /2 , because a fraction of Ce ions at the surface of particles may exist as Ce +3 even in non-reducing conditions (Kimmel et al 2006). The Ce 3+ /Ce 4+ ratio may be close to 1 for very small particles (<2 nm), but decreases to ~0.01 for larger ones (>15 nm) (Bae et al 2004).…”

Section: Resultsmentioning

confidence: 99%

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Structure and phase stability of nanocrystalline Ce1−x Ln x O2−x/2−δ (Ln = Yb, Lu) in oxidizing and reducing atmosphere

et al. 2008

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The structure and phase evolution of nanocrystalline Ce1−xLnxO2−x/2−δ (Ln = Yb, Lu, x = 0 − 1) oxides upon heating in H2 was studied for the first time. Up to 950 °C the samples were single-phase, with structure changing smoothly with x from fluorite type (F) to bixbyite type (C). For the Lu-doped samples heated at 1100 °C in the air and H2, phase separation into coexisting F- and C-type structures was observed for ~0.40 < x < ~0.70 and ~0.25 < x < ~0.70, respectively. It was found also that addition of Lu3+ and Yb3+ strongly hinders the crystallite growth of ceria during heat treatment at 800 and 950 °C in both atmospheres. Valency of Ce and Yb in Ce0.1Lu0.9O1.55−δ and Ce0.95Yb0.05O1.975−δ samples heated at 1100 °C was studied by XANES and magnetic measurements. In the former Ce was dominated by Ce4+, with small contribution of Ce3+ after heating in H2. In the latter, Yb existed exclusively as 3+ in both O2 and H2.

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Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Structure and phase stability of nanocrystalline Ce1−x Ln x O2−x/2−δ (Ln = Yb, Lu) in oxidizing and reducing atmosphere

et al. 2008

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“…In view of growing depletion of natural resources and increasing cost of energy, rationalization of production processes has become an urgency [1][2][3][4]. A method for production of new materials proposed as an alternative to high-temperature treatment, sol-gel, hydrothermal, sonochemical or Pechini processes is mechanochemical synthesis [1][2][3][4][5][6][7][8][9][10][11]. Its main advantage is simplicity as the method is based on milling of all kinds of reagents in high-energy mills [1,2,4,8,9].…”

Section: Introductionmentioning

confidence: 99%

“…According to the literature data on the oxide system Y 2 O 3 -Yb 2 O 3 [10,11], in this system, a solid solution of the general formula Y 2-x Yb x O 3 is formed. It has been obtained by high-temperature (1400°C) treatment of mixtures of oxides containing Y 2 O 3 and Yb 2 O 3 , of defined compositions (solid-state reactions), for a few days [10].…”

Section: Introductionmentioning

confidence: 99%

Mechanochemical synthesis and thermal stability of phases in the Y2O3–Yb2O3 system

Piz

Filipek

Jabłoński

2019

J Therm Anal Calorim

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Substitutional, continuous solid solution of the general formula Y 2-x Yb x O 3 was obtained from the mixture of Y 2 O 3 and Yb 2 O 3 oxides, for the first time by the mechanochemical method in a high-energy ball milling. The monophasic samples of nanocrystalline solid solution for x [ 0.00 and x \ 2.00 were examined by the methods: XRD, DTA, SEM, IR and UV-Vis-DR. As follows from the results, the solid solution crystallizes in cubic system and is isostructural with Y 2 O 3 and Yb 2 O 3. The solution is stable in the air atmosphere up to at least 900°C, and its decomposition temperature decreases with the increase in x, that is, with decreasing number of Yb 3? ions replacing Y 3? ions in the crystal lattice of Y 2 O 3. The energy band gap estimated for the solid solution varies from * 5.30 eV for x = 0.50 to * 4.90 eV for x = 1.50, which means that it is an insulator.

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“…Al 2 O 3 and Al 2 O 3 -ZrO 2 Fibers Obtained by Biotemplete with Low Thermal Conductivity http://dx.doi.org/10.5772/59011 corresponding to cristobalite zirconia between temperatures of 1200-1600°C. The crystalline phase of Al 2 O 3 -ZrO 2 shown inFigure 2has a cubic structure[20], not being detected by Raman.…”

mentioning

confidence: 98%

Al2O3 and Al2O3-ZrO2 Fibers Obtained by Biotemplete with Low Thermal Conductivity

Delbrücke¹,

Gouvêa²,

Raubach³

et al. 2015

Sintering Techniques of Materials

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Certain porous materials have special properties and functions that cannot normally be obtained by conventional dense counterparts. Therefore, porous materials are now used in many applications such as final products and in various technological processes. Macroporous materials are used in various forms and compositions in everyday life; e.g. polymeric foams, packaging, lightweight aluminum structures in buildings, aircraft, and as a porous ceramic for water [1,2]. A growing number of applications that require advanced ceramics have appeared in recent decades, especially in environments where high temperatures, extended wear and corrosive environments are present. Such applications include the filtration of molten metals, high temperature insulation, support for catalytic reactions [3], filtration of particulates from exhaust gases of diesel engines and filtration of hot gases in various corrosive industrial processes, for example [4-6]. The advantages of using porous ceramic for these applications are generally a high melting point, suitable electronic properties, good corrosion resistance and wear resistance in combination with the characteristics acquired by the replacement of the solid material by voids in the component. Such characteristics include low thermal mass, low thermal conductivity, permeability control, high surface area, low density, high specific strength and a low dielectric constant [1,7]. These properties can be tailored for each specific application by controlling the composition and microstructure of the porous ceramic [8,9].

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Formation and characterization of nanocrystalline binary oxides of yttrium and rare earths metals

Cited by 11 publications

References 15 publications

Structure and phase stability of nanocrystalline Ce1−x Ln x O2−x/2−δ (Ln = Yb, Lu) in oxidizing and reducing atmosphere

Structure and phase stability of nanocrystalline Ce1−x Ln x O2−x/2−δ (Ln = Yb, Lu) in oxidizing and reducing atmosphere

Mechanochemical synthesis and thermal stability of phases in the Y2O3–Yb2O3 system

Al2O3 and Al2O3-ZrO2 Fibers Obtained by Biotemplete with Low Thermal Conductivity

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