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Wyniki wyszukiwania dla: FERROELECTRIC PROPERTIES
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Effect of Cr and Mn doping on ferroelectric and dielectric properties of Li1.72Na0.28Ge4O9 single crystals
PublikacjaLi1.72Na0.28Ge4O9 single crystals pure and slightly doped with chromium and manganese, obtained by Czochralski growth, were investigated for their ferroelectric and dielectric properties. The change in stoichometry of Li2− x Na x Ge4O9 (x = 0.28) crystals doped with Cr and Mn (0.1 mol.%) had an influence on the value of ferroelectric-to-paraelectric phase transition temperature, T c. The applied doping affects the T c value by...
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Nonlinear electrical properties of glass-ceramics nanocomposites containing ferroelectric nanocrystallites of Bi2VO5.5
PublikacjaNonlinear A.C. impedance measurements were conducted in the 50BiV-50SrBAlO nanocomposite as a function of frequency, temperature and A.C. voltage. This material is ferroelectric below temperature of 730 K, and above 730 K is a good ion-conductor. For this nanocomposite a low A.C. voltage of 1 V rms is enough to observe high nonlinearities. The origin of these nonlinear effects depends on the temperature and frequency. In the high...
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Imaging of ferroelectric properties of sinter by means of Piezoresponse Force Microscopy
Dane BadawczeFerroelectricity is a property of certain materials [1], characterized by a spontaneous electrical polarization that can be reversed by applying an external electric field. Ferroelectric properties can be used to make capacitors with adjustable capacity. The permeability of ferroelectrics is not only regulated, but usually also very high, especially...
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Raman studies of ferroelectric ceramics.
PublikacjaPrzedstawiono potencjał aplikacyjny spektroskopii Ramana w diagnostyce procesu technologicznego wytwarzania cienkowarstwowych struktur perowskitowych o strukturze Ba(Ti1 xZrx)O3, posiadających możliwość strojenia przenikalności elektrycznej za pomocą pola elektrycznego. Skonfigurowano systemy pomiarowe do badania zarówno próbek objętościowych, jak i struktur cienkowarstwowych. Zidentyfikowano najistotniejsze linie w widmach ramanowskich,...
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Ferroelectric LTCC tape for piezoelectric applications
PublikacjaOpisano opracowanie surowej taśmy LTCC do zastosowań piezoelektrycznych. Wybór bazuje na modyfikowanej lantanem kompozycji cyrkoniano-tytanioołowiu (PLZT). Opisano proces produkcji taśmy, wykonanie próbek ceramicznych z użyciem tej taśmy, zastosowane metody pomiarowe oraz dielektryczne i piezoelektryczne parametry wyprodukowanych próbek.
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Mixed ionic-electronic conductivity and structural properties of strontium-borate glass containing nanocrystallites of Bi2 VO5.5
PublikacjaSamples of strontium borate glass containing bismuth vanadate nanocrystallites were prepared. Nanocomposites containing up to 45mol% of the Bi2VO5.5 phase exhibit electrical properties closer to the strontium-borate glass than to the ferroelectric Bi2VO5.5 ceramic. The glass matrix still may contain some part of bismuth and vanadium ions even after crystallization process and there is too little of crystalline phase to observe...
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Raman and infrared investigation of ferroelectric ceramics. IV Workshop on Atomic and Molecular Physics.
PublikacjaZastosowano spektroskopię absorbcyjną w podczerwieni i spektroskopię Ramana do badania ceramik ferroelektrycznych o kompozycji Ba(Ti1-xZrx)O3. Ceramiki te charakteryzują się możliwością przestrajania przenikalności elektrycznej za pomocą pola elektrycznego.
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Influence of Sn and Pb Ions Substitutions on Dielectric Properties of Barium Titanate
PublikacjaThe results of the microstructural and dielectric measurements of (Ba1-xPbx)(Ti1-xSnx)O3 (BPTSx) (x = 0, 0.05, 0.10, 0.30) polycrystalline samples are presented. The samples were obtained by means of a high temperature synthesis and their expected stoichiometry was confirmed by energy dispersive spectroscopy (EDS) measurements. The dielectric properties of BPTSx were studied with the use of broadband dielectric spectroscopy. The...
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Magnetoelectric, spectroscopic, optical and elastic properties of Co-doped BaTiO3 ceramics
Publikacjahe BaTiO3 perovskite is widely used in the electronic technology due to its dielectric, piezoelectric and ferroelectric properties and is a well-known base for obtaining a promising multifunctional material. In this paper we report the extensive studies on the Co-doped BaTiO3 ceramics for the wide range cobalt content. Full structural characterization of studied samples in a 20–450 K range was provided. The results of research...
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Critical behaviour of the smectic A*–C* phase transition and electroclinic effect of ferroelectric liquid crystals with terphenyl rigid core
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ALTERNATIVE, DIRECT SYNTHESIS METHOD OF THE CERAMIC SOLID SOLUTIONS BASED ON BaTiO3 THROUGH A HIGH ENERGY BALL MILLING
PublikacjaPolycrystalline samples BaTiO3 and the solid solutions Ba0.9Sr0.1TiO3, Ba0.9Sr0.1Ti0.9Sn0.1O3, Ba0.9Sr0.1Ti0.8Sn0.2O3 were obtained by means of a mechanochemical treatment based on the high-energy ball milling technique and next a high temperature solid state reaction method. The influence of synthesis condition on microstructural, dielectric and ferroelectric properties of obtained solid solutions were investigated. The structure...
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Gigantic electro-chemo-mechanical properties of nanostructured praseodymium doped ceria
PublikacjaSome oxygen defective fluorites are non-Newnham electrostrictors, i.e., the electromechanical response does not depend on their dielectric properties. Here, we show gigantic electrostriction in nanocrystalline 25 mol% praseodymium doped ceria (PCO) bulk ceramics. The material was fabricated with a fieldassisted spark plasma sintering (SPS) process from high-purity nanoscale PCO powders (<20 nm). The SPS process consolidates the...
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Structural, electrical, and magnetic study of La-, Eu-, and Er- doped bismuth ferrite nanomaterials obtained by solution combustion synthesis
PublikacjaIn this work, the multiferroic bismuth ferrite materials Bi0.9RE0.1FeO3 doped by rare-earth (RE = La, Eu, and Er) elements were obtained by the solution combustion synthesis. Structure, electrical, and magnetic properties of prepared samples were investigated by X-ray photoelectron spectroscopy, Mössbauer spectroscopy, electrical hysteresis measurement, broadband dielectric spectroscopy, and SQUID magnetometry. All obtained nanomaterials...
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Właściwości elektryczne szkło-ceramiki zawierającej ferroelektryczną fazę BiV
PublikacjaKompozyty szklano - ceramiczne zawierające nanokryształy posiadają właściwości fizyczne, które nie są możliwe do uzyskania w innych materiałach. Dzięki możliwości wytworzenia szkło - ceramik posiadających kryształy o różnej wielkości (nano, mikro...) i różnorodnego typu, można w istotny sposób kontrolować właściwości elektryczne takich materiałów. Stała dielektryczna faz ferroelektrycznych jest bardzo wrażliwa na zmiany rozmiarów...
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Piezoresponse force microscopy and dielectric spectroscopy study of Ba0.6Sr0.4TiO3 thin films
PublikacjaResearch on synthesis, characterization and determination of processing – structure – property relationships of commercially important ferroelectric thin films has been performed. The sol-gel-type solution deposition technique was applied to produce good quality thin films of Ba0.6Sr0.4TiO3 (BST60/40) chemical composition on the stainless steel substrates. The thin films were characterized in terms of their microstructure, crystal...
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Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
PublikacjaThree new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize...
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High-accuracy polarimetric studies on lead germanate single crystals
PublikacjaA high-accuracy polarimetric technique has been used for the characterization of a lead germanate ferroelectric single crystal. The measurement results of the linear and circular birefringence in the [010] direction at a wavelength of 633 nm under the influence of an electric field are presented. Gyration–electric field hysteresis loops at alternative crystal positions in the polarization system have been used to determine the...
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Fabrication of La-Doped Bi4Ti3O12 Ceramics
PublikacjaLa-modified Bi4Ti3O12 is a typical ferroelectric, piezoelectric and electro-optic material, having relatively low coercive field, low dielectric constant, high Curie temperature and high breakdown strength. Goal of the present research was to apply mixed oxide method for fabrication of BiTLax ceramics, study its chemical composition, crystalline structure and microstructure. The compound BiTLax for x=0, 0.25, 0.5, 0.75 ceramic...