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5 results on '"FACETED GRAINS"'

1. Low traces of acetone detection with WO3-based chemical sensors.

Author

Stanoiu, Adelina, Vlaicu, Ioana D., Iacoban, Alexandra C., Mihalcea, Catalina G., Ghica, Corneliu, Florea, Ovidiu G., Dinu, Ion V., Mercioniu, Ionel, and Simion, Cristian E.

Subjects
*CHEMICAL detectors, *ACETONE, *ALUMINUM oxide, *GAS dynamics, *HUMIDITY
Abstract

This work presents the ability of WO 3 -based sensors to detect low traces of acetone, specifically within the range of 0.25–5 ppm, specific to the in-field atmosphere. The WO 3 powder was synthesised through the hydrothermal method. Morpho-structural investigations showed a monoclinic structure and a good crystallization of the WO 3 powder, containing well-grown and faceted grains along low-index crystallographic planes. The paste obtained by mixing the powder with propanediol was screen-printed as a thick layer onto commercial alumina substrates, obtaining the chemical sensors. A dynamic computer-controlled Gas Mixing System was utilized to ensure controlled airflow with variable relative humidity and acetone concentrations. The sensor response was explained based on physico-chemical equations, taking into consideration pre-adsorbed species of oxygen and water, both of which are relevant constituents of atmospheric conditions. The results highlight the applicative potential of WO 3 , having a good signal-to-noise ratio in relative humidity conditions up to 90% and a pronounced sensitive selectivity to acetone. • Hydrothermally grown WO 3 exhibits a monoclinic structure revealed by XRD analysis. • TEM images show faceted grains measuring several hundreds of nanometers in size. • The sensors consist of thick WO 3 layers deposited onto Al 2 O 3 substrates. • Sensor response increases with both acetone concentration and relative humidity. • No cross-sensitivity with exhalation interferents (NH 3 and CO 2) was observed. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Recrystallization and investigation of bismuth thin films by means of electron beam in transmission electron microscope

Author

Kolosov, V. Y., Yushkov, A. A., Veretennikov, L. M., Kolosov, V. Y., Yushkov, A. A., and Veretennikov, L. M.

Abstract

Thin bismuth films obtained by vacuum deposition were recrystallized under electron beam of scanning electron microscope at 5 kV and examined in a transmission electron microscope at 200 kV. In recrystallized films, various microstructures were detected: single-crystal, polycrystalline and amorphous regions, more or less faceted grains, single crystals and untransparent drop-shaped particles. In the crystallized film, a strong internal bending of the crystal lattice is detected, up to 110 deg/μm. © Published under licence by IOP Publishing Ltd.

Published
2018

3. Microstructure of (Ba 0.75 ,Sr 0.25 )TiO 3 based glass-ceramics doped by Mn

Author

Turygin, A. P., Abramov, A. S., Alikin, D. O., Chezganov, D. S., Esin, A. A., Baturin, I. S., Song, X., Zhang, T., Zhang, Y., Hu, K., Zhao, Z., Shur, V. Y., Turygin, A. P., Abramov, A. S., Alikin, D. O., Chezganov, D. S., Esin, A. A., Baturin, I. S., Song, X., Zhang, T., Zhang, Y., Hu, K., Zhao, Z., and Shur, V. Y.

Abstract

We studied microstructure, surface morphology, and domain structure of (Ba 0.75 ,Sr 0.25 )TiO 3 based glass-ceramics with different amount of Mn additive (from 0 to 0.5%) prepared from melted and quenched mixed powders using several microscopic methods. The as-quenched sample was annealed and subjected to a controlled crystallization in air for 2h at temperatures 850 and 950?C. It was shown that the addition of the Mn up to 0.5% had no impact on morphology and domain structure. The dendrite structure was revealed in the samples crystallized at 850?C. The geometry of the clusters was analysed in terms of fractal approach. The faceted grains with size about 150 nm were found in ceramics annealed at 950?C. Individual grains demonstrated non-uniform piezoresponse, which could be attributed to existence of domain structure. © 2018 Institute of Physics Publishing. All rights reserved.

Published
2018

4. Microstructure of (Ba 0.75 ,Sr 0.25 )TiO 3 based glass-ceramics doped by Mn

Author

Denis Alikin, V. Ya. Shur, Kangjia Hu, Xiaozhen Song, Yunhui Zhang, Zhangyuan Zhao, Tao Zhang, Ivan Baturin, A. A. Esin, A. P. Turygin, Dmitry Chezganov, and A S Abramov

Subjects
FACETED GRAINS, Materials science, Morphology (linguistics), Analytical chemistry, SCANNING PROBE MICROSCOPY, 02 engineering and technology, 01 natural sciences, law.invention, Dendrite (crystal), GLASS CERAMICS, law, CONTROLLED CRYSTALLIZATION, 0103 physical sciences, Ceramic, Crystallization, 010302 applied physics, HYDROPHOBICITY, MICROSCOPIC METHODS, Doping, INDIVIDUAL GRAINS, 021001 nanoscience & nanotechnology, Microstructure, FRACTALS, PIEZORESPONSE, visual_art, visual_art.visual_art_medium, MICROSTRUCTURE, DENDRITE STRUCTURES, 0210 nano-technology, FRACTAL APPROACH, TITANIUM OXIDES, DOMAIN STRUCTURE
Abstract

We studied microstructure, surface morphology, and domain structure of (Ba 0.75 ,Sr 0.25 )TiO 3 based glass-ceramics with different amount of Mn additive (from 0 to 0.5%) prepared from melted and quenched mixed powders using several microscopic methods. The as-quenched sample was annealed and subjected to a controlled crystallization in air for 2h at temperatures 850 and 950?C. It was shown that the addition of the Mn up to 0.5% had no impact on morphology and domain structure. The dendrite structure was revealed in the samples crystallized at 850?C. The geometry of the clusters was analysed in terms of fractal approach. The faceted grains with size about 150 nm were found in ceramics annealed at 950?C. Individual grains demonstrated non-uniform piezoresponse, which could be attributed to existence of domain structure. © 2018 Institute of Physics Publishing. All rights reserved. The equipment of the Ural Centre for Shared Use “Modern Nanotechnology” Ural Federal University was used. The research was made possible by Russian Foundation for Basic Research (grant 18-52-53032) and state task of Ministry of education and science of the Russian Federation (No. 3.4993.2017/6.7). The work was supported partially by Government of the Russian Federation (act 211, agreement 02.A03.21.0006). et al.;NT-MDT Spectrum Instruments;Ostec-ArtTool Ltd.;Promenergolab LLC;Russian Foundation for Basic Research;Taylor and Francis Group

Published
2018
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5. Recrystallization and investigation of bismuth thin films by means of electron beam in transmission electron microscope

Author

V. Yu Kolosov, L. M. Veretennikov, and A. A. Yushkov

Subjects
History, FLUXES, SCANNING ELECTRON MICROSCOPY, FACETED GRAINS, Materials science, POLYCRYSTALLINE, chemistry.chemical_element, Education, Bismuth, ELECTRON BEAMS, THIN FILMS, INTERNAL BENDING, Thin film, Composite material, BISMUTH THIN FILMS, Recrystallization (metallurgy), SHAPED PARTICLES, RADIATION EFFECTS, BISMUTH, SINGLE CRYSTALS, TRANSMISSION ELECTRON MICROSCOPY, BISMUTH FILM, Computer Science Applications, ELECTRONS, AMORPHOUS REGIONS, chemistry, Transmission electron microscopy, Cathode ray, CRYSTALLIZED FILMS, RECRYSTALLIZATION (METALLURGY), AMORPHOUS FILMS
Abstract

Thin bismuth films obtained by vacuum deposition were recrystallized under electron beam of scanning electron microscope at 5 kV and examined in a transmission electron microscope at 200 kV. In recrystallized films, various microstructures were detected: single-crystal, polycrystalline and amorphous regions, more or less faceted grains, single crystals and untransparent drop-shaped particles. In the crystallized film, a strong internal bending of the crystal lattice is detected, up to 110 deg/μm. © Published under licence by IOP Publishing Ltd. Partial support of project 3.6121.2017/8.9 (The Ministry of Education and Science of the Russian Federation) and Agreement No 02.A03.21.0006 (Act 211 Government of the Russian Federation) is acknowledged.

Published
2018
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