D. Mishchuk | Taras Shevchenko National University of Kyiv (original) (raw)
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Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ ... more Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ 4/3 − 2 x Nb 2 O 6 (Ln = La, Nd) perovskite-like solid solutions. Increasing the Na content of the solid solutions reduces their symmetry from Pmmm to Pmmn and then to Pbcm. The structural and dielectric properties of the solid solutions belonging to the three space groups are studied.
Journal of Applied Physics, 2007
It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in... more It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in strontium barium niobate relaxor ferroelectric causes a decrease in vacancy content of the samples and a linear variation of unit cell volume with sodium concentration. The variation of c lattice parameter with sodium concentration is determined by deformations of the NbO6 oxygen octahedrons
Inorganic Materials, 2004
Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ ... more Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ 4/3 − 2 x Nb 2 O 6 (Ln = La, Nd) perovskite-like solid solutions. Increasing the Na content of the solid solutions reduces their symmetry from Pmmm to Pmmn and then to Pbcm. The structural and dielectric properties of the solid solutions belonging to the three space groups are studied.
Journal of Applied Physics, 2007
It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in... more It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in strontium barium niobate relaxor ferroelectric causes a decrease in vacancy content of the samples and a linear variation of unit cell volume with sodium concentration. The variation of c lattice parameter with sodium concentration is determined by deformations of the NbO6 oxygen octahedrons
Colloidal Nanoparticles for Biomedical Applications XI, 2016
Inorganic Materials, 2006
ABSTRACT
Inorganic Materials, 2010
Polycrystalline nonstoichiometric Ba(Co1/3Nb2/3)O3 (BCN) materials have been synthesized and inve... more Polycrystalline nonstoichiometric Ba(Co1/3Nb2/3)O3 (BCN) materials have been synthesized and investigated. Deviations from stoichiometry have been shown to lead to the formation of crystalline Ba6CoNb9O30 (barium deficiency) and Ba8CoNb6O24 (cobalt deficiency). The effect of phase composition on the microwave dielectric properties of BCN has been studied. The results demonstrate that the dielectric properties of BCN-based materials can be tuned by varying
Inorganic Materials, 2007
ABSTRACT The formation of the columbite-structure magnesium niobate MgNb2O6 is a multistep proces... more ABSTRACT The formation of the columbite-structure magnesium niobate MgNb2O6 is a multistep process. Single-phase material can only be obtained through long-term high-temperature heat treatment. Deviations from stoichiometry have a significant effect on the microwave quality factor Q of the material: magnesium-deficient ceramics contain small amounts of Nb2O5 and have relatively low Q values, whereas an excess of magnesium leads to the formation of Mg4Nb2O9 (alpha-alumina structure) as an impurity phase, thereby drastically increasing the electrical Q.
Inorganic Materials, 2004
ABSTRACT
Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ ... more Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ 4/3 − 2 x Nb 2 O 6 (Ln = La, Nd) perovskite-like solid solutions. Increasing the Na content of the solid solutions reduces their symmetry from Pmmm to Pmmn and then to Pbcm. The structural and dielectric properties of the solid solutions belonging to the three space groups are studied.
Journal of Applied Physics, 2007
It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in... more It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in strontium barium niobate relaxor ferroelectric causes a decrease in vacancy content of the samples and a linear variation of unit cell volume with sodium concentration. The variation of c lattice parameter with sodium concentration is determined by deformations of the NbO6 oxygen octahedrons
Inorganic Materials, 2004
Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ ... more Experimental evidence is presented for the formation of continuous series of Ln 2/3 − x Na 3 x ᮀ 4/3 − 2 x Nb 2 O 6 (Ln = La, Nd) perovskite-like solid solutions. Increasing the Na content of the solid solutions reduces their symmetry from Pmmm to Pmmn and then to Pbcm. The structural and dielectric properties of the solid solutions belonging to the three space groups are studied.
Journal of Applied Physics, 2007
It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in... more It has been shown that the aliovalent substitution of sodium ions for strontium or barium ions in strontium barium niobate relaxor ferroelectric causes a decrease in vacancy content of the samples and a linear variation of unit cell volume with sodium concentration. The variation of c lattice parameter with sodium concentration is determined by deformations of the NbO6 oxygen octahedrons
Colloidal Nanoparticles for Biomedical Applications XI, 2016
Inorganic Materials, 2006
ABSTRACT
Inorganic Materials, 2010
Polycrystalline nonstoichiometric Ba(Co1/3Nb2/3)O3 (BCN) materials have been synthesized and inve... more Polycrystalline nonstoichiometric Ba(Co1/3Nb2/3)O3 (BCN) materials have been synthesized and investigated. Deviations from stoichiometry have been shown to lead to the formation of crystalline Ba6CoNb9O30 (barium deficiency) and Ba8CoNb6O24 (cobalt deficiency). The effect of phase composition on the microwave dielectric properties of BCN has been studied. The results demonstrate that the dielectric properties of BCN-based materials can be tuned by varying
Inorganic Materials, 2007
ABSTRACT The formation of the columbite-structure magnesium niobate MgNb2O6 is a multistep proces... more ABSTRACT The formation of the columbite-structure magnesium niobate MgNb2O6 is a multistep process. Single-phase material can only be obtained through long-term high-temperature heat treatment. Deviations from stoichiometry have a significant effect on the microwave quality factor Q of the material: magnesium-deficient ceramics contain small amounts of Nb2O5 and have relatively low Q values, whereas an excess of magnesium leads to the formation of Mg4Nb2O9 (alpha-alumina structure) as an impurity phase, thereby drastically increasing the electrical Q.
Inorganic Materials, 2004
ABSTRACT