Characterization of KNbO3 nanoplates synthesized by a stirred hydrothermal process

Krad, Imen; Bidault, O.; Saı̈d, Sonia; Maaoui, Mohamed El

doi:10.1016/j.matlet.2015.06.121

Cited by 10 publications

(3 citation statements)

References 24 publications

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“…On the other hand, there is a reduction of this constant for the CFO samples (ϵ'~5420), KN (ϵ'~1930) and the heat-treated composites at 400 and 500 • C (ϵ'~2218 and 2472), respectively. The values of the dielectric constant of KN and pure CFO are well established, and the values found in this work are comparable to the values reported in the literature [49,50]. On the other hand, few studies are found that establish the dielectric constant at room temperature for KN:CFO composites.…”

Section: Resultssupporting

confidence: 89%

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Wermuth

Venturini

Guaglianoni

et al. 2021

Ceramics International

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In this work, multiferroic composites were produced from CoFe 2 O 4 and KNbO 3 mixtures via control of the heat treatment temperature. For this, CoFe 2 O 4 nanoparticles were produced by sol-gel method, while KNbO 3 was synthesized by microwave-assisted hydrothermal synthesis. The powders were homogenized and subjected to heat treatment at 300, 400 and 500 • C for 5 h. The structural, electrical and magnetic properties were characterized. The results of X-ray diffraction indicated that there was no formation of secondary phases with heat treatment. Raman vibrational modes confirmed the presence of KNbO 3 and CoFe 2 O 4 in the prepared composites. SEM analysis showed that the composite microstructure consists of smaller ferrite particles arranged on the surface of largest cubic KNbO 3 particles. The improvement of coercivity (H C = 382.1Oe) and dielectric constant (ϵ'~7860) was observed for the composite thermally treated at 300 • C. The obtained results show the potential application of KN:CFO composites for multifunctional devices.

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Section: Resultssupporting

confidence: 89%

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Wermuth

Venturini

Guaglianoni

et al. 2021

Ceramics International

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“…The morphology of KN is one of the important factors affecting the performance, and the device prepared using the powder with controllable morphology has better performance. Among related research studies, nanoscale KN particles of various shapes such as nanowires, , nanoblocks, and nanosheets − have been developed continuously. Compared with randomly oriented polycrystalline materials, layered structure ferroelectrics have become an optimum choice for ferroelectric and piezoelectric materials due to their higher anisotropy and more spontaneous polarization allowing orientation. − In recent years, many researchers have focused on low-dimensional semiconductor photocatalysts [such as one-dimensional (1D) nanowires or two-dimensional (2D) nanosheets] as a means of further enhancing the rate of the photocatalytic reaction.…”

Section: Introductionmentioning

confidence: 99%

Oriented Plate-like KNbO₃ Polycrystals: Topochemical Mesocrystal Conversion and Piezoelectric and Photocatalytic Responses

et al. 2023

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KNbO3 (KN) with a perovskite structure is an outstanding representative of lead-free piezoelectric materials, and its mesocrystals have broad application prospects in the fields of catalysis, energy storage, and conversion. However, the formation conditions of KN mesocrystals reported so far are difficult owing to their high aspect ratio and excellent preferred orientation. In this study, the solvothermal process was used successfully to prepare the flake-like potassium salt of Lindquist hexaniobate (K8Nb6O19·10H2O). Subsequently, the precursor niobate was calcined to prepare two-dimensional (2D) plate-like KN mesocrystals. The formation mechanism of the plate-like KN mesocrystals is further revealed from a paired topochemical mesocrystal conversion of K8Nb6O19·10H2O niobate. Finally, the microscopic piezoelectric and photocatalytic responses of the obtained plate-like KN mesocrystals were investigated. The high piezoelectric coefficient of plate-like KN mesocrystals implies that excellent charge separation promotes the photocatalytic performance of rhodamine B (RhB). This study provides a strategy for the efficient application of 2D oriented materials in the field of piezoelectricity and photocatalysis.

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“…Therefore, the current trend in the direction for the preparation of nanoscale multifunctional materials is to meet the requirements of functional devices of very small size. As a result, various shapes of nanoscale KN particles such as nanorods, nanoneedles, nanoblocks, and nanosheets have been developed. − For the preparation of alkaline earth niobate MNbO 3 (M = Li, Na, K), Nb 2 O 5 and M 2 CO 3 were usually used as the starting materials at a high temperature. A high alkalinity is usually required for the formation of KN through hydrothermal reaction. ,,, Higher alkalinity is beneficial to the formation of pure phase KN, which is probably due to the formation of [NbO 6 ] 7– ion under high alkaline conditions.…”

Section: Introductionmentioning

confidence: 99%

Solvothermal Reaction and Piezoelectric Response of Oriented KNbO₃ Polycrystals

Yang

Wang

et al. 2020

Inorg. Chem.

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KNbO 3 (KN) piezoelectric polycrystals were prepared by a two-step solvothermal reaction process with the managed organic solvents as reaction mediums at a low temperature for a short time. In the solvothermal reaction system, the formation mechanism of polycrystalline KN is mainly the dissolution−deposition mechanism. The influences of alkalinity, viscosity, and the polarity for reaction mediums on the formation of the niobates were investigated. The chemical reaction mechanisms of niobate products and formation mechanism of niobate crystals from the precursor were clarified. The regulating and controlling mechanism of the phase compositions, the morphologies, and the lattice constants for the niobates obtained in varied reaction mediums were revealed. The obtained KN piezoelectric polycrystals are constructed from oriented KN nanocrystals. Piezoelectric hysteresis loops of cuboid KN polycrystals were detected for the first time. A prepared cuboid KN polycrystal shows an average d 33 * value of 32 pm/V. The study provides a strategy for the development of oriented KN piezoelectric materials to apply the orientation engineering.

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Characterization of KNbO3 nanoplates synthesized by a stirred hydrothermal process

Cited by 10 publications

References 24 publications

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Oriented Plate-like KNbO₃ Polycrystals: Topochemical Mesocrystal Conversion and Piezoelectric and Photocatalytic Responses

Solvothermal Reaction and Piezoelectric Response of Oriented KNbO₃ Polycrystals

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Characterization of KNbO3 nanoplates synthesized by a stirred hydrothermal process

Cited by 10 publications

References 24 publications

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Enhancement of magnetic and dielectric properties of KNbO3–CoFe2O4 multiferroic composites via thermal treatment

Oriented Plate-like KNbO3 Polycrystals: Topochemical Mesocrystal Conversion and Piezoelectric and Photocatalytic Responses

Solvothermal Reaction and Piezoelectric Response of Oriented KNbO3 Polycrystals

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Oriented Plate-like KNbO₃ Polycrystals: Topochemical Mesocrystal Conversion and Piezoelectric and Photocatalytic Responses

Solvothermal Reaction and Piezoelectric Response of Oriented KNbO₃ Polycrystals