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Naji, M. |
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Motta, Antonella |
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Aletan, Dirar |
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Mohamed, Tarek |
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Ertürk, Emre |
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Taccardi, Nicola |
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Kononenko, Denys |
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Petrov, R. H. | Madrid |
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Alshaaer, Mazen | Brussels |
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Bih, L. |
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Casati, R. |
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Muller, Hermance |
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Kočí, Jan | Prague |
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Šuljagić, Marija |
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Kalteremidou, Kalliopi-Artemi | Brussels |
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Azam, Siraj |
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Ospanova, Alyiya |
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Blanpain, Bart |
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Ali, M. A. |
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Popa, V. |
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Rančić, M. |
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Ollier, Nadège |
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Azevedo, Nuno Monteiro |
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Landes, Michael |
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Rignanese, Gian-Marco |
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Hříbalová, Soňa
University of Chemistry and Technology
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (11/11 displayed)
- 2023Modeling the thermal conductivity of carbon nanotube (CNT) nanofluids and nanocomposites – a fresh restartcitations
- 2022Quasi-laminate and quasi-columnate modeling of dielectric and piezoelectric properties of cubic-cell metamaterialscitations
- 2022Transmittance predictions for transparent alumina ceramics based on the complete grain size distribution or a single mean grain size replacing the whole distributioncitations
- 2021Light scattering models for describing the transmittance of transparent and translucent alumina and zirconia ceramicscitations
- 2021Theoretical study of the influence of carbon contamination on the transparency of spinel ceramics prepared by spark plasma sintering (SPS)citations
- 2021Microstructure and Young's modulus evolution during re-sintering of partially sintered alumina-zirconia composites (ATZ ceramics)citations
- 2021PARTIALLY SINTERED LEAD-FREE CERAMICS FROM PIEZOELECTRIC POWDERS PREPARED VIA CONVENTIONAL FIRING AND SPARK PLASMA SINTERING (SPS) - CHARACTERIZATION OF MICROSTRUCTURE AND DIELECTRIC PROPERTIEScitations
- 2021Computer modeling of systematic processing defects on the thermal and elastic properties of open Kelvin-cell metamaterialscitations
- 2021Sintering aids, their role and behaviour in the production of transparent ceramicscitations
- 2020Light scattering and extinction in polydisperse systemscitations
- 2020Temperature dependence of Young's modulus and damping of partially sintered and dense zirconia ceramicscitations
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article
PARTIALLY SINTERED LEAD-FREE CERAMICS FROM PIEZOELECTRIC POWDERS PREPARED VIA CONVENTIONAL FIRING AND SPARK PLASMA SINTERING (SPS) - CHARACTERIZATION OF MICROSTRUCTURE AND DIELECTRIC PROPERTIES
Abstract
This work deals with dielectric properties of lead-free ceramics from piezoelectric powders and focuses on the preparation and characterization of potassium-sodium niobate (K0.5Na0.5NbO3, KNN) and barium titanate (BaTiO3, BT) ceramics. Ceramic samples with different porosity were prepared from commercial KNN and BT powders by conventional firing in air or spark plasma sintering (SPS) at temperatures 600 - 1000 degrees C for KNN and 900 - 1300 degrees C for BT, resulting in partially or fully sintered microstructures. Bulk density, apparent density and open porosity were determined using the Archimedes method and closed and total porosities were calculated on the basis of theoretical densities. For both types of ceramics, the porosity decreases with increasing sintering temperature, and for identical temperatures the porosity of SPS samples is lower than for conventional firing, because the pressure applied during SPS promotes densification. For KNN the influence of SPS on the porosity is much larger than for BT. With increasing SPS temperature KNN exhibits a moderate decrease of the alkali content. The results of dielectric property measurements and their frequency dependence via impedance spectroscopy in the range from 10 or 100 Hz to 1 MHz show that the relative permittivity decreases in all cases with frequency and is usually higher for ceramics prepared via SPS than for conventional firing. This can be explained by the lower porosity and smaller grain size. The absolute values of the relative permittivity at 1 kHz are 134 - 532 (conventional firing) and 148 - 3780 (SPS) for KNN, and 753 - 1801 (conventional firing) and 923 - 10 380 (SPS) for BT ceramics.