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| 2. |
- Jonsson, Torbjörn, 1970, et al.
(författare)
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The influence of H2O on iron oxidation at 600?C: a microstructural study.
- 2008
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Ingår i: Materials Science Forum. - 1662-9752 .- 0255-5476. ; 595-598:Pt. 2, High Temperature Corrosion and Protection o, s. 1005-1012
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of iron in dry O2 and in wet O2 (40% H2O) has been studied at 600°C. The oxide microstructure was investigated by SEM/EDX, FIB and XRD. Iron forms a layered scale in dry and wet oxygen at 600°C. The scale consists of a top hematite layer, a middle magnetite layer and a wüstite layer close to the scale metal interface. All three layers grow with time, but with different growth rates, the overall growth being approximately parabolic. The presence of water vapour increases the rate of oxidation and affects the evolution of the oxide microstructure. The higher rate of oxidation in the presence of water vapour is due to an increased growth rate of the magnetite layer and, especially, of the hematite layer, while the growth of the wüstite layer is not affected. It is suggested that water vapour influences grain boundary transport in the hematite layer.
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| 3. |
- Pujilaksono, Bagas, 1965, et al.
(författare)
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Paralinear Oxidation of Chromium in O2 + H2O Environment at 600–700 °C
- 2008
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Ingår i: Oxidation of Metals. - 1573-4889 .- 0030-770X. ; 70:3-4, s. 163-188
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of chromium in dry O2 and in O2 + 10%H2O at 600 and 700 °C is studied. Scale morphology is investigated by several methods, including scanning electron microscopy (SEM) of cross sections prepared by focussed ion beam milling (FIB). In O2 + H2O at 600 and 700 °C, chromium forms a duplex scale consisting of an inner barrier oxide and a discontinuous outer oxide made up of blade-shaped crystals. Thermogravimetric (TG) measurements show that water vapour influences chromium oxidation by causing vaporization of the protective oxide, resulting in paralinear oxidation kinetics. An extension of the original treatment by Tedmon is deduced, which allows for the determination of the evaporation rate constant k s and the parabolic oxidation rate constant k d from TG data acquired during short exposures. The results show that k d is the same in dry O2 and in O2 + 10%H2O. Equivalently, the transport properties of chromia are the same in the two environments. The equilibrium constant of CrO2(OH)2 formation from chromia is reported. The activation enthalpy of the vaporization reaction is determined.
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| 4. |
- Andersson, Thorvald, 1946, et al.
(författare)
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Preparation and characterization of the ITO surface and the Al/Alq3/ITO heterostructure for OLEDs
- 2007
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Ingår i: Materials Science and Engineering B. ; 145, s. 48-56
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Tidskriftsartikel (refereegranskat)abstract
- We have made a detailed investigation of structure and chemical composition in thermally grown Al/Alq3/ITO layer structures intended for light emission. The different parts of the structure were studied by X-ray photoelectron spectroscopy and microscopical techniques. The indium tinoxide substrate surface consisted of grains 20–50 nm in diameter and about 5 nm in height, which also showed molecular sized sub-grain features. Due to the ambient the ITO surface was covered by a 1 nm thick hydrocarbon layer which serves as the actual surface on which an organic layer is deposited for device fabrication. A structural model for the indium tin oxide surface, on which the small molecules were deposited, was suggested. The substrate surface was treated to study the relation between the surface manipulation and the hole injection barrier. Such surface modification significantly improved the performance of a single layer Alq3 organic light emitting diode. Depth profiling of the complete structure, revealed that the aluminium contact mostly consisted of aluminium oxide with some intermixing of carbon. Further, variations of the atomic concentration of the elements In, Sn, C and O and a minor shift in their binding energies were measured. Both, position and shape of the oxygen and indium peaks were changed during argon ion sputtering. At the Alq3/ITO interface an indium–oxygen compound, different from that on the original surface, hadformed. Various effects of the compositional findings on the light emission are discussed.
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| 6. |
- Pujilaksono, Bagas, 1965, et al.
(författare)
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X-ray photoelectron spectroscopy studies of indium tin oxide nanocrystalline powder
- 2005
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Ingår i: Materials Characterization. ; 54:1, s. 1-7
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Tidskriftsartikel (refereegranskat)abstract
- Indium tin oxide films and coatings are widely used and can be produced by different techniques including dip and spin-coating of suspensions of nano-particles. To achieve high quality films the nano-powder has to be fully characterized. Hence, three co-precipitated nanocrystalline indium tin oxide powders of different particle size were investigated by use of X-ray photoelectron spectroscopy. The analysis indicated that indium and tin are in oxide state, i.e. no metallic component could be observed. In addition, measurements by use of X-ray diffraction, scanning electron microscopy/energy dispersive X-ray spectroscopy and transmission electron microscopy were performed. They showed that indium tin oxide primary particles are slightly elliptical and facetted in shape, respectively. The powders have a body center cubic lattice type and the lattice parameter is 1.01 nm. Measured by both X-ray photoelectron spectroscopy and energy dispersive X-ray, the tin content was determined to be 5-6 at.%.
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