| 1. |
- Mihailova, B., et al.
(författare)
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Raman scattering in locally inhomogeneous oxide crystals
- 2003
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Ingår i: Phase Transitions. - : Informa UK Limited. - 0141-1594 .- 1029-0338. ; 76:1-2, s. 17-32
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Tidskriftsartikel (refereegranskat)abstract
- Local-scale atomic arrangements in three types of oxide crystalline materials with structural defects, self-bonded molecular sieves, ferroelastics and relaxor ferroelectricity, are investigated by Raman spectroscopy. The experimentally observed spectral data are analysed through normal mode calculations for structural species representative of the intermediate range order in the solid. In the case of molecular sieves, the important role of incipient structural species for producing crystalline silicalite-1 and zeolite beta spheres of mm size is shown. In the case of ferroelastics, further insights on structural perturbation across the domain walls in monoclinic Pb 3(PO4)2 are provided. In the case of relaxors, the local structure and related dynamical effects in PbSc0.5Nb 0.5O3 and PbSc0.5Nb0.5O3 is revealed.
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| 2. |
- Bagheri, B., et al.
(författare)
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Comparsion study of different simulation codes for positive streamers
- 2017
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Ingår i: Proceedings of the International Conference on Phenomena in Ionized Gases (ICPIG).
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- For streamer simulations a range of computational models have been developed by various groups for various purposes. These models differ in dimensionality (2D, 3D), model type (particle, fluid or hybrid approach and further differentiation), their numerical implementation, type of grid and its refinement, and their spatial/temporal discretization. The aim of the present study is to benchmark the results of different simulation codes for axisymmetric single positive streamers in air at 1 bar and 300 K using a fluid model.
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| 3. |
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| 4. |
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| 5. |
- Mihailova, B., et al.
(författare)
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Infrared spectroscopic study of a γ-mercaptopropyltrimethoxysilane monolayer on a gold surface
- 1999
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Ingår i: Journal of Materials Chemistry. - 0959-9428 .- 1364-5501. ; 9:7, s. 1507-1510
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Tidskriftsartikel (refereegranskat)abstract
- Reflectance-absorption infrared spectra of ?-mercaptopropyltrimethoxysilane (?-MPT) adsorbed on Au (111)-oriented films are analyzed on the basis of the calculated vibrational modes of a monomer, a dimer and n-membered rings of SiO3R (R=CH2CH2CH2SAu). The results show that the ?-MPT molecules adsorbed on the Au surface are partially hydrolyzed and that the orientation of the methyl groups and propyl chains are near perpendicular to the surface. After a hydrolysis procedure, the SiO3 groups in ?-MPT form a quasi two-dimensional system built predominantly of 6-membered puckered Si-O rings. Additional treatment of the ?-MPT monolayer with a surface-charge-reversing cationic polymer disrupts the connectivity and increases the topological disorder in the silicate system.
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| 6. |
- Mihailova, B., et al.
(författare)
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Vibrational spectroscopy study of the structure of silicalite-1 films on a gold surface
- 1999
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Ingår i: Microporous and Mesoporous Materials. - 1387-1811 .- 1873-3093. ; 32:3, s. 297-304
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Tidskriftsartikel (refereegranskat)abstract
- The structure of silicalite-1 films grown on seeded gold surfaces is investigated by modelling the observed changes in the infrared reflection absorption (IRRA) spectra of samples treated for different times in the synthesis solution. The results show that a gradual deformation of the five-membered silicon-oxygen rings occurs during the first 11 h of the hydrothermal treatment which leads to breaking of Si---O---Si linkages and to formation of linear defects along the c-axis. Interactions between the dislocations and the grain boundaries during the further growth of the film provoke the appearance of void spaces in the grain boundary interface which may cause incipient cracking in the silicalite-1 films on seeded gold surfaces. The range 1000-1300 cm-1 in the IRRA spectra is found to be appropriate for estimating the quality of silicalite-1 films grown on metal surfaces.
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