High temperature neutron diffraction study of the Al2O3–Y2O3 system

Medraj, Mamoun; Hammond, Robert P.; Parvez, M.A.; Drew, R. A. L.; Thompson, W. T.

doi:10.1016/j.jeurceramsoc.2005.12.008

Cited by 114 publications

(47 citation statements)

References 20 publications

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“…Al 2 O 3 powder was used as a reference material to observe the effect of heat treatment on the as-solidified sample. No apparent endothermic or exothermic peaks were detected up to 1673 K. The as-solidified RAlO 3 sample did not show any phase transition, i.e., the formed o-RAlO 3 phase remained even after annealing at 1673 K. This suggests that [47][48][49] However, we did not find any metastable phases in both the as-prepared and annealed samples.…”

Section: G Phase Identification and Microstructure Of Crystalline Ramentioning

confidence: 58%

Thermal and optical properties of glass and crystalline phases formed in the binary R2O3-Al2O3 (R = La-Lu and Y) system

Kumar

Ishikawa

Basavalingu

et al. 2013

Journal of Applied Physics

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Rare-earth aluminate (RAlO 3 , R ¼ La-Lu and Y) glass and crystalline phases were prepared by containerless levitation in an aerodynamic levitation furnace. In the RAlO 3 system, La, Nd and Sm aluminum perovskites solidified as glass and Eu-Lu and Y aluminum perovskites solidified as crystalline phases. The glass forming region decreased with decreasing ionic radius of the rareearth element. Scanning electron microscopy images and x-ray diffraction results revealed the formation of a single RAlO 3 phase from the undercooled melt. The glass transition temperature, T g , and density increased and the molar volume decreased with decreasing rare-earth element ionic radius. The refractive index at 589 nm exceeds 1.85 in each composition and a transparency of approximately 72% was achieved for the LaAlO 3 glass. V C 2013 AIP Publishing LLC.

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Section: G Phase Identification and Microstructure Of Crystalline Ramentioning

confidence: 58%

Thermal and optical properties of glass and crystalline phases formed in the binary R2O3-Al2O3 (R = La-Lu and Y) system

Kumar

Ishikawa

Basavalingu

et al. 2013

Journal of Applied Physics

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“…Al 2 O 3 ceramic coatings can effectively protect TiAl alloys against oxidation at high temperatures and no diffusion occurs at the interface during service [14,15], which is beneficial to both the properties of the substrate alloys and Al 2 O 3 coatings [13]. Al 2 O 3 coatings can be prepared by many techniques, including plasma spray (PS) [16], electron-beam physical vapor deposition (EB-PVD) [17], sol-gel [18], and electro-deposition [19,20].…”

Section: Introductionmentioning

confidence: 99%

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Yang

Jiang

Ding

et al. 2018

Metals

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Al 2 O 3 coatings were prepared on Ti-45Al-8.5Nb alloys via cathodic plasma electrolysis deposition (CPED) in both 1.2 M Al(NO 3 ) 3 aqueous and ethanolic solutions. Different voltages were also applied during the deposition process to optimize coating properties. Coatings deposited in both solutions mainly consisted of γ-Al 2 O 3 , with some Al(OH) 3 found in coatings prepared in aqueous solution. Coatings prepared in ethanol solution exhibited better oxidation resistance at 900 • C as well as better substrate adhesion, which was mainly due to smaller crater sizes on coating surfaces. The deposition process was discussed in detail and the reason for the smaller craters examined. The results suggested that solution surface tension mainly influenced the average diameter of hydrogen bubbles that formed on cathode surfaces during the process. Smaller bubbles lead to both lower current densities on cathodes and smaller crater sizes on coatings.

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“…Thus, because of high costs of YAPmonocrystals manufacturing and the expected different behaviour of polycrystalline ceramics under the relevant excitation, manufacturing of RE-doped YAP powders or polycrystalline ceramics is a challenging task in nowadays research community. The results on preparation of YAP powders/nanopowders are scarce and they show complexity of that phase formation [7][8][9][10][11][12][13][14]. The topic of this work is to check the possibility of manufacturing the monophase YAP powder or polycrystalline ceramics by the solid-state reaction method using different particle size of starting powders and methods of homogenization.…”

Section: Introductionmentioning

confidence: 99%

Influence of Homogenization and Micro/Nano Source of Starting Powders on Format Ion of the Single YAP Phase

Michalik¹,

Pawlik²,

Plewa³

et al. 2016

Archives of Metallurgy and Materials

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Manufacturing high purity polycrystalline YAlO3 (YAP) ceramics could replace monocrystalline YAP thus recently it is an interesting task for low cost producers of scintillators. The paper presents influence of different source of initial oxide powders (micro/nano powders of Y2O3 and Al2O3) and the method of their homogenization on the formation of a YAP phase. The solid state reaction method was used to prepare YAP powder or ceramic pellets. After preheating, all samples in the form of powders and pellets were heat-treated in the temperature range of 1050-1650 °C. DTA method was applied for examination of the phase crystallization in the tested system. X-ray diffraction method (XRD) was used for characterization of the phase composition. X-ray microanalysis (EDS) was used to control homogeneity in the small areas. Morphology of the resultant samples are presented on SEM pictures. The results show a significant influence of the starting powders on the homogeneity, purity and temperature of formation of the main phase.

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High temperature neutron diffraction study of the Al2O3–Y2O3 system

Cited by 114 publications

References 20 publications

Thermal and optical properties of glass and crystalline phases formed in the binary R2O3-Al2O3 (R = La-Lu and Y) system

Thermal and optical properties of glass and crystalline phases formed in the binary R2O3-Al2O3 (R = La-Lu and Y) system

Influence of Solvent and Electrical Voltage on Cathode Plasma Electrolytic Deposition of Al2O3 Antioxidation Coatings on Ti-45Al-8.5Nb Alloys

Influence of Homogenization and Micro/Nano Source of Starting Powders on Format Ion of the Single YAP Phase

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