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Structural and electronic properties of Ga2O3-Al2O3 alloys Open
Ga2O3 is emerging as an important electronic material. Alloying with Al2O3 is a viable method to achieve carrier confinement, to increase the bandgap, or to modify the lattice parameters. However, the two materials have very different grou…
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Advances in fabrication of ceramic corundum abrasives based on sol–gel process Open
Corundum abrasives with good chemical stability can be fabricated into various free abrasives and bonded abrasive tools that are widely used in the precision machining of various parts. However, these abrasives cannot satisfy the machining…
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Evolution of corundum-structured III-oxide semiconductors: Growth, properties, and devices Open
The recent progress and development of corundum-structured III-oxide semiconductors are reviewed. They allow bandgap engineering from 3.7 to ∼9 eV and function engineering, leading to highly durable electronic devices and deep ultraviolet …
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RETRACTED: Effects of Cr2O3 Content on Microstructure and Mechanical Properties of Al2O3 Matrix Composites Open
Al2O3-Cr2O3 refractories are completely substitution solid solutions and can effectively resist slag erosion when used as an industrial furnace lining. In order to provide suitable chromium corundum refractory with excellent slag resistanc…
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Ferroelectricity in corundum derivatives Open
The search for new ferroelectric (FE) materials holds promise for broadening\nour understanding of FE mechanisms and extending the range of application of FE\nmaterials. Here we investigate a class of ABO3 and A2BB'O6 materials that can\nb…
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Magnetostriction-polarization coupling in multiferroic Mn2MnWO6 Open
Double corundum-related polar magnets are promising materials for multiferroic and magnetoelectric applications in spintronics. However, their design and synthesis is a challenge, and magnetoelectric coupling has only been observed in Ni 3…
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Thermal stability of α-Ga2O3 films grown on c-plane sapphire substrates via mist-CVD Open
The thermal stability of α-Ga2O3 films grown on c-plane sapphire substrates was investigated. A strong correlation was found between thermal stability and film thickness: the more the α-Ga2O3 films maintained the α-phase upon heating at hi…
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Lattice dynamics of a mist-chemical vapor deposition-grown corundum-like Ga2O3 single crystal Open
The lattice dynamical properties of the corundum-like α-phase of Ga2O3 are investigated by means of Raman scattering experiments and ab-initio calculations. A high-quality, single-crystal thick epilayer was grown on sapphire by the mist-ch…
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Supported Ag Nanoparticles and Clusters for CO Oxidation: Size Effects and Influence of the Silver–Oxygen Interactions Open
Supported Ag catalysts on silica and corundum have been synthesized applying an improved impregnation technique. The resulting Ag particle sizes can be divided into three categories concerning: (I) bulk-like, (II) nanoparticles of 1-6 nm, …
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Hydrothermal Stability of High-Surface-Area α-Al<sub>2</sub>O<sub>3</sub> and Its Use as a Support for Hydrothermally Stable Fischer–Tropsch Synthesis Catalysts Open
Nanocrystalline corundum synthesized by ball milling of boehmite is found to be exceptionally robust toward chemical weathering, a common problem of transition aluminas in different applications, most notably in the case of supported catal…
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Ultrafast Non‐Equilibrium Phase Transition Induced Twin Boundaries of Spinel Lithium Manganate Open
Defect engineering is demonstrated to be an important factor in enhancing the electrochemical performance of lithium‐ion batteries by improving structural stability and ion diffusion. However, conventional synthetic methods have long and c…
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A Quantitative Description of the Causes of Color in Corundum Open
The color of a gemstone is inextricably linked to its chemical composition, yet the quantitative relationship between color and chemistry is poorly understood in most cases.Here we use corundum to present a comprehensive quantitative descr…
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Origin of isolated olivine grains in carbonaceous chondrites Open
We report microscopic, cathodoluminescence, chemical, and O isotopic measurements of FeO‐poor isolated olivine grains (IOG) in the carbonaceous chondrites Allende (CV3), Northwest Africa 5958 (C2‐ung), Northwest Africa 11086 (CM2‐an), and …
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Size-dependent electronic properties of nanomaterials: How this novel class of nanodescriptors supposed to be calculated? Open
In this study, the influence of the size on the electronic properties (e.g. electronic energy) of three nanometal oxides: ZnO, TiO2, and Al2O3 were investigated. The wurtzite, rutile and corundum type of clusters were selected to represent…
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η Carinae's Dusty Homunculus Nebula from Near-infrared to Submillimeter Wavelengths: Mass, Composition, and Evidence for Fading Opacity Open
Infrared observations of the dusty, massive Homunculus Nebula around the luminous blue variable η Carinae are crucial to characterize the mass-loss history and help constrain the mechanisms leading to the great eruption. We present the 2.4…
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Effect of alumina addition on the phase transformation and crystallisation properties of refractory cordierite prepared from amorphous rice husk silica Open
The effect of alumina addition of 5–30% by weight on phase transformation and crystallisation properties of refractory cordierite ceramics prepared from amorphous rice husk silica followed by sintering treatment at temperature of 1230 °C w…
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Alumina Extraction from Coal Fly Ash via Low-Temperature Potassium Bisulfate Calcination Open
Owing to the depletion of bauxite and increasing demand for alumina, calcination methods for extracting alumina from coal fly ash (CFA) were developed. However, these methods have disadvantages such as the need for high temperatures and th…
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Theoretical modeling of charge trapping in crystalline and amorphous Al<sub>2</sub>O<sub>3</sub> Open
The characteristics of intrinsic electron and hole trapping in crystalline and amorphous Al2O3 have been studied using density functional theory (DFT). Special attention was paid to enforcing the piece-wise linearity of the total energy wi…
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Microstructure and mechanical properties of melt-grown alumina-mullite/glass composites fabricated by directed laser deposition Open
Melt-grown alumina-based composites are receiving increasing attention due to their potential for aerospace applications; however, the rapid preparation of high-performance components remains a challenge. Herein, a novel route for 3D print…
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Room Temperature Magnetically Ordered Polar Corundum GaFeO<sub>3</sub> Displaying Magnetoelectric Coupling Open
The polar corundum structure type offers a route to new room temperature multiferroic materials, as the partial LiNbO3-type cation ordering that breaks inversion symmetry may be combined with long-range magnetic ordering of high spin d5 ca…
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Abrasion Resistance of S235, S355, C45, AISI 304 and Hardox 500 Steels with Usage of Garnet, Corundum and Carborundum Abrasives Open
The steel presents wide field of application. Abrasive wear resistance of steel relies mainly on microstructure, hardness as well as on the abrasive material properties. Moreover, the selection of a resistant to abrasion grade of steel see…
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Exploring the origin of clumpy dust clouds around cool giants Open
Context. Dust grains forming in the extended atmospheres of AGB stars are critical for the heavy mass loss of these cool luminous giants, as they provide radiative acceleration for the stellar winds. Characteristic mid-IR spectral features…
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Growth of 2-Inch α-Ga<sub>2</sub>O<sub>3</sub> Epilayers via Rear-Flow-Controlled Mist Chemical Vapor Deposition Open
The effectiveness of rear-flow-controlled mist chemical vapor deposition (mist CVD) for the growth of 2-inch α-Ga2O3 epilayers was studied. The numerical simulation indicated that the low velocity of the flow is appropriate for inducing an…
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Lightweight Refractory Concrete Based on Aluminum-Magnesium-Phosphate Binder Open
The paper is discussing the results of works on preparation of refractory concrete based on aluminum-magnesia-phosphate binder. The modification of magnesia phosphate binder by aluminum allows increasing the stability of the binder, as wel…
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Ruby Deposits: A Review and Geological Classification Open
Corundum is not uncommon on Earth but the gem varieties of ruby and sapphire are relatively rare. Gem corundum deposits are classified as primary and secondary deposits. Primary deposits contain corundum either in the rocks where it crysta…
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Gem Corundum Deposits of Greece: Geology, Mineralogy and Genesis Open
Greece contains several gem corundum deposits set within diverse geological settings, mostly within the Rhodope (Xanthi and Drama areas) and Attico-Cycladic (Naxos and Ikaria islands) tectono-metamorphic units. In the Xanthi area, the sapp…
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Geology of Corundum and Emerald Gem Deposits: A Review Open
The great challenge of geographic origin determination is to connect the properties and features of individual gems to the geology of their deposits.Similar geologic environments can produce gems with similar gemological properties, making…
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Reactive SPS of Al<sub>2</sub>O<sub>3</sub>–RE:YAG (RE = Ce; Ce+Gd) composite ceramic phosphors Open
Ultrafine-grained Al2O3–rare earth:yttrium aluminium garnet (Al2O3–RE:YAG) (RE = Ce; Ce+Gd) composite ceramics were obtained for the first time by reactive spark plasma sintering (SPS) using commercially available initial oxide powders. Th…
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Influence of Carrier Gases on the Quality of Epitaxial Corundum-Structured α-Ga2O3 Films Grown by Mist Chemical Vapor Deposition Method Open
This report systematically investigates the influence of different carrier gases (O2, N2, and air) on the growth of gallium oxide (Ga2O3) thin films on c-plane sapphire substrates by using the mist-CVD method. Although XRD and Raman measur…
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Rheology of PDMS-corundum sand mixtures from the Tectonic Modelling Lab of the University of Bern (CH) Open
This dataset provides rheometric data of silicone (Polydimethylsiloxane, PDMS SGM36)-corundum sand mixtures used for analogue modelling in Zwaan et al. (2016, 2017), Zwaan and Schreurs (2017) and in the Tectonic Modelling Lab of the Instit…