A Quantitative Description of the Causes of Color in Corundum
The absorption coefficient is, of course, dependent on the concentration of the chromophore. If we want to compare two different chromophores but the samples have different chromophore concentrations, we can divide the absorption coefficient of each chromophore by its concentration in absorbers/cm 3 (note that 1 ppma in corundum is …
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Growth of corundum-structured In
The XRD results suggested formation of highly-crystalline α-In 2 O 3. The α-In 2 O 3 thin films showed n-type semiconductor property with reasonable electron …
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Structure and creep of mullite-corundum refractories
A binder exhibiting low porosity and localization of the glass phase can ensure a 50–100 times reduction in the creep limit as compared to a material in which the binder mass has a low density and the corundum and mullite crystals are separated by thin films of glass. The total concentration of the glass phase, the Al 2 O 3 content in the ...
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Photoelectron spectroscopic study on electronic …
By combining HAXPES and SXPES, the degree of the band bending was estimated as approximate 0.5 eV. The carrier concentration calculation by the …
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Nanomaterials Versus Ambient Ultrafine Particles: An …
Cardiopulmonary: Epidemiologic Evidence . Epidemiology studies clearly demonstrate links between PM 10 and PM 2.5 with both short-term and long-term health effects, particularly on the respiratory and cardiovascular systems (Dockery et al. 1993).However, PM includes a range of particle sizes, and very few studies have included …
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Preparation and characterization of Sn-doped
Sn-doped gallium oxide (Ga2O3:Sn) films were deposited on β-Ga2O3 (100) substrates by metal organic chemical vapor deposition method. The Sn concentration was varied from 1 to 12 % (atomic ratio). The influences of Sn-doping concentration on structure, raman, and photoelectric properties of the films were investigated in detail. The …
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Aluminas
Corundum. There are a few forms of aluminum oxide, and corundum being the most common. The structure of corundum can be viewed as a hexagonal close …
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Influence of Carrier Gases on the Quality of Epitaxial Corundum …
This report systematically investigates the influence of different carrier gases (O 2, N 2, and air) on the growth of gallium oxide (Ga 2 O 3) thin films on c-plane sapphire substrates by using the mist-CVD method.Although XRD and Raman measurements show that the pure corundum-structured α-Ga 2 O 3 with single (0006) plane orientation was …
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Adsorption of different valence metal cations on
The adsorption of metal ions increases with the ion concentration. ... The surface hydration film has an electric double-layer ... Allen et al. [35] explored the adsorption of three metal cations, that is, Al 3+, Cr 3+, and Mn 2+, onto quartz (SiO 2) and corundum (Al 2 O 3) surfaces at pH 3.8 using QCM-D measurements. The configuration of the ...
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Azimuthal Anisotropy of Rhombohedral (Corundum Phase) …
The pseudomorphic growth (of thin films with sufficiently low Ga content) is deducted from reciprocal space maps (RSMs). Two films on r- and r ′-planes with almost identical Al concentration x ≈ 0.905 are compared in Figure 4 for the (41.6) reflex for r-plane substrate and the (rotated by 60°) corresponding (5-4.6) reflex for the r ′ substrate. …
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Optical properties of corundum-structured In2O3
The optical properties of a single-phase corundum-structured In 2 O 3 epilayer grown by a mist chemical vapor deposition method have been studied. Raman scattering measurements on a c face and on a lateral face reveal all of the seven Raman-active modes of the corundum structure, with good adherence to the Raman selection …
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Effect of manganese doping of corundum on the content …
Water is the main volatile impurity in the crystals of Mn-doped corundum. An increase in the concentration of manganese in corundum increases the water content in the low-temperature form and affects the high-temperature water release by the diffusion mechanism in different ways: for MnCl 2-precursor, the content of the high-temperature …
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Corundum nanostructure ITO film fabrication: An approach …
Corundum (hexagonal) structure indium tin oxide (h-ITO) nanocrystals have been synthesized by subjecting an aqueous solution of In and Sn chlorides (S…
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A power device material of corundum-structured α-Ga2O3 …
Corundum-structured oxides have been attracting much attention as next-generation power device materials. A corundum-structured α-Ga 2 O 3 successfully demonstrated power device operations of Schottky barrier diodes (SBDs) with the lowest on-resistance of 0.1 mΩ cm 2.The SBDs as a mounting device of TO220 also showed low …
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MRS Advances © 201 Materials Research Society 7 799
Since there are a variety of corundum-structured materials, including D-Al2O3 and D-In2O3 besides D-Ga2O3, band gap engineering from 3.7 eV to a9 eV is possible by alloying these compounds [14]. Corundum-structured D-Ga2O3 is grown by safe and cost-effective mist chemical vapor deposition (CVD), which is effective to supply devices at low cost ...
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Aluminum solubility in rutile (TiO 2 )
Electron probe microanalysis (EPMA) measurements of rutile crystals grown in equilibrium with corundum show that the concentration of Al increases with …
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thin films grown by mist chemical vapor deposition
The electrical conductivity was obtained in the films with the Sn concentration of less than 0.34 %. The crystal structure was maintained to α-Ga 2 O 3 in this Sn concentration range, while the crystal quality rapidly deteriorates when the concentration of Sn was over 0.34 %.
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Alumina
Chemistry at extreme conditions: approaching the Earth's major interface. Leonid Dubrovinsky, ... Innokenty Kantor, in Advances in High-Pressure Technology for Geophysical Applications, 2005. 3.2 Chemical interaction of iron and corundum at high pressure and temperature. Aluminum oxide (Al 2 O 3) together with SiO 2, MgO, and …
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Structural and electronic properties of Ga2O3-Al2O3 alloys
For x values in the vicinity of 0.71, the energy difference between corundum and monoclinic is small and can easily be overcome at high temperatures, explaining why some experiments have observed the monoclinic structure for Al concentrations above 71% 17–19,21,25–27 or the corundum structure for Al concentrations lower than 71%. …
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Corundum dissolution in concentrated sodium hydroxide …
The corundum (α-alumina) core has been considered as a suitable candidate for investment casting of hollow, high pressure turbine engine airfoils due to its excellent properties. However, the efficiency of removing alumina cores in concentrated caustic solution cannot meet the needs of industrial production. In this paper, the effects …
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Indium oxide: In2O3
The concentration of the V In in the Sn-donor-doped sample was higher than that in Mg-acceptor-doped samples, ... Growth of corundum-structured In 2 O 3 thin films on sapphire substrates with Fe 2 O 3 buffer layers. J. Cryst. Growth, 364 (2013), pp. 30-33. View PDF View article View in Scopus Google Scholar
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Photoluminescence and optical transmission of diamond …
Synthetic diamonds with low nitrogen concentration show exciton luminescence even at room temperature [11]. In these conditions, the band-A intensity of luminescence is very low. ... a CVD diamond film of ∼1 ... The corundum samples had different degree of coloration from pale-pink to deep-red, which affected the PL and OT …
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Optical properties of corundum-structured In2O3
In the UV region, the imaginary part of the dielectric function shows two distinct onsets of strong absorption associated with direct band-to-band transitions at …
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Materials | Free Full-Text | Improving Corrosion Resistance of …
The corrosion of refractories in contact with high temperature aluminum-magnesium alloys leads to contamination of the Al-Mg alloy products by solid impurities from degraded refractories. Where both the spinel and corundum phases form in the refractories, cracks are generated and propagated by diffusion of molten Al-Mg, resulting in severe …
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RIR
method for mine dust analysis by film techniques. The development of the Geiger-counter diffractometer in 1945 ... the concentration of a and s must be known exactly. The fact that the RIR, when properly measured, ... A particularly important case is when corundum is chosen as the internal standard reference material and integrated
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Electrical Conductive Corundum-Structured α-Ga 2 O 3 Thin Films …
Carrier concentration of Sn‐doped α‐Ga2O3 films is controlled in the range of 1017–1019 cm−3 by changing the Sn/Ga concentration ratio in source solution. α‐Ga2O3 films on m‐plane ...
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Corundum-quartz metastability: the influence of a …
Within the corundum plate rims grown on corundum single crystals, we measured a chemical profile for Si, which displayed a maximum concentration at the contact between single crystal and corundum plates followed by gradually decreasing Si content along the plate rim with increasing distance to the single crystal (Fig. 3).
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Evolution of corundum-structured III-oxide semiconductors: …
Corundum-structured α-Ga 2 O 3 is mostly obtained on a sapphire (α-Al 2 O 3) substrate, and this is probably due to the similarity in lattice structure between the epilayer and the substrate, despite the lattice mismatch (3.5 and 4.8% along the c- and a-axes, respectively).Interestingly for the growth, many of the studies on α-Ga 2 O 3 have used …
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Epitaxial corundum-VTiO3 thin films grown on c-cut sapphire
Corundum structured VTiO 3 has been grown as epitaxial films on c-cut sapphire by laser molecular beam epitaxy.The properties of the film were characterized by reflection high energy electron diffraction, X-ray diffraction, transmission electron microscopy (TEM), and photoemission spectroscopy. All the structural probes clearly indicate the …
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Properties and mechanism of formation of α-alumina (Corundum) film …
For example, in KHSO 4-NaHSO 4 (2 : 1 mol) mixture at 180°C, at 1 A/dm 2 by applying 0–160 V for 30 min, a white and mat oxide film is produced on aluminium, which is rather porous (density 2·96) but very hard and is not attacked by any chemicals such as HF, H 2 SO 4, H 3 PO 4, NaOH etc. of any concentration. Coating ratio is 1·76–1·81 ...
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