| 1. |
- Gejke, Cecilia, 1973, et al.
(författare)
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The effect of lithium insertion on the structure of tin oxide-based glasses
- 2001
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Ingår i: Journal of Power Sources. - 0378-7753. ; 97-98, s. 226-228.
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Tidskriftsartikel (refereegranskat)abstract
- Two different SnO-based glasses, Sn2B3O6.5 and Sn2B2AlO6.5, have been examd. with FT-IR and Raman spectroscopy at different stages during the first electrochemical cycle. Some disruption of the connection between borate units in the network occurred during cycling. There was also an irreversible formation of Li3BO3 that can be related to the large capacity loss.
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| 2. |
- Dyson, P J, et al.
(författare)
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Determination of hydrogen concentration in ionic liquids and the effect (or lack of) on rates of hydrogenation
- 2003
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Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; :19, s. 2418-2419
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Tidskriftsartikel (refereegranskat)abstract
- The solubility of hydrogen and the corresponding Henry coefficients for 11 ionic liquids have been determined in situ at 100 atm H(2) pressure and are much lower than expected; attempts to correlate the solubility of hydrogen in the ionic liquids with the rate of reaction for the hydrogenation of benzene to cyclohexane in these solvents have been made.
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| 3. |
- Gejke, Cecilia, 1973, et al.
(författare)
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Structural investigation of the Li+ ion insertion/extraction mechanism in Sn-based composite oxide glasses
- 2001
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Ingår i: Journal of Physics and Chemistry of Solids. - 0022-3697. ; 62, s. 1213-1218.
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Tidskriftsartikel (refereegranskat)abstract
- The effect of lithium insertion for two Sn-based composite oxide glasses, Sn2BPO6 and Sn2P2O7, was examined during the first electrochemical discharge/charge cycle. Electrodes based on these glasses were analysed with micro-Raman spectroscopy at different steps during the cycle. In-situ X-ray diffraction has been used to confirm the amorphous state during the lithium insertion and extraction process. No alloy formation between Li and Sn could be discerned throughout the first cycle. It was found that when lithium enters the electrode, a reaction at the surface of the glass particles takes place resulting in Li3PO4, Li2O and SnO2 formation. The charge compensation mechanism is thought to be the reduction of Sn2+ to Sn. The formation of Li3PO4 is found to be irreversible and is as such partly responsible for the large observed capacity loss during the first cycle.
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| 4. |
- Cesar, F, et al.
(författare)
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Synthesis and characterization of carbon filaments grown from Pd3P colloids
- 2000
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Ingår i: Journal of Materials Research. - 0884-2914. ; 15:9, s. 1857-1859
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous carbon filaments were synthesized by catalytic pyrolysis of propene over Pd3P colloids. The channel close to the center of the filaments usually contained particles, which were analyzed by analytical electron microscopy to be palladium. The palladium particles could be found anywhere along the filament. The carbon filaments were of two types and of different diameters, about 8-15 nm and about 40-80 nm. The thinner type of filament shows a channel diameter of about 5 nm. The type of filament produced depends on the reaction conditions. Increased reaction time results in a large number of filaments, whereas an increased propene gas flow results in more of the thicker type of filaments.
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| 5. |
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| 6. |
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| 7. |
- Hansson, Kristina, 1971, et al.
(författare)
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On the Mechanism of MoSi2 Pesting in the Temperature Range 400–500°C
- 2000
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Ingår i: Ceramic Engineering and Science Proceedings. - 0196-6219 .- 1940-6339. ; 21:4, s. 469-476
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of a MoSi2 composite was studied in the temperature range 400–500°C. The peak pesting temperature was identified and the oxidation kinetics was observed up to a holding time of 4000 hours. The reaction kinetics was tracked using thermogravimetric analysis :IS well iis oxide thickness nieasurenients. A detailed analysis of the morphology and composition of the oxide was performed using SEM and EDX. The peak pesting temperature was found to be 470°C. The reaction kinetics in static air could be described with two consecutive parabolic oxidation curves, one up to 500 hours and another between 500–4000 hours. With a higher water vapor coiitent the kinetics showed linear behwior. MoO3 evaporation took place during the entire duration of the oxidation. The oxide appeared to grow by inward diffusion of oxygen to the oxidehulk interface.
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| 8. |
- Hansson, Kristina, 1971, et al.
(författare)
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Oxidation behaviour of a MoSi2-based composite in different atmospheres in the low temperature range (400–550 °C)
- 2004
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Ingår i: Journal of the European Ceramic Society. - : Elsevier BV. - 1873-619X .- 0955-2219. ; 24:13, s. 3559-3573
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation characteristics of a MoSi2-based composite within the temperature range of 400–550 °C were investigated. The effects of temperature and water vapour on oxidation were examined. The oxidation kinetics were studied using a thermobalance, while the morphology and composition of the oxides were examined using XRD, ESEM/EDX, and SEM/EDX.The peak oxidation rates in dry O2 and View the MathML source were found to occur at temperatures of approximately 510 and 470 °C, respectively. Within the temperature range of accelerated oxidation (400–500 °C), the oxidation rate in View the MathML source was substantially higher than that in dry O2. At higher temperatures, the oxidation rate decreased, and the magnitude of the decrease was steeper and occurred at a lower temperature for View the MathML source (510 °C) than for O2 (550 °C). Furthermore, the rate of depletion of molybdenum (Mo) from the oxide scales during oxidation increased with increasing temperature and water vapour content. It appears that Mo loss is a key process influencing the protective properties of the oxide layer on the MoSi2 composite. A potential mechanism for the different oxidation behaviours in O2 and View the MathML source is proposed.
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| 9. |
- Hansson, Kristina, 1971, et al.
(författare)
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The influence of water vapor on the oxidation of MoSi2 at 450 °C
- 2001
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Ingår i: Materials Science Forum. - 1662-9752 .- 0255-5476. ; 369-372, s. 419-426
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Tidskriftsartikel (refereegranskat)abstract
- The oxidation of a MoSi2 composite was studied in dry air, oxygen and oxygensaturated with 10% water vapour at 450°C. The kinetics were investigated using TGA as well as oxide thickness measurements. Detailed analyses were performed on the morphology and composition of the oxide using XRD, ESEM, SEM, and EDX. It is shown that the oxidation rate increases drastically in the presence of water vapour, and the growth of Mo03 crystals on the oxide surface increases considerably. The different regions in the oxide cross-section are Mo-depleted compared with the corresponding regions in the bulk when oxidised in oxygen saturated with 10% water vapour. However, the samples oxidised in dry oxygen only shows Mo-depletion in some outer parts of the oxide. Accelerated growth of the MoSi2-oxide layer during exposure in 02+10%H20 compared to that in 02 can be related to the fact that more volatile Mo-species form in the presence of water vapour, resulting in a substantial loss of Mo03 from the inner part of the oxide. The voids left behind are not healed by the silica at this low temperature, which leaves the oxide with an open structure. As a result, the oxidation rate increases.
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| 10. |
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