Ferroelectric Materials
Mostrando 1-12 de 29 artigos, teses e dissertações.
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1. Study of Structural and Electric Properties of the PZT 52/48 Doped With Er+3
The scientific community has shown a growing interest in relating to the ferroelectric materials and it has made an effort to develop them. Among these several ferroelectric materials, we proposed to investigated Pb(ZrTi)O3 doped with distinct Er+3 concentrations. Our aim was to investigate how the erbium affects the PZT electrical properties. To determine t
Mat. Res.. Publicado em: 25/11/2019
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2. Síntese da perovskita [KNbO3]0,9[BaNi0,5Nb0,5O3-δ]0,1 por combustão em solução
Resumo O desenvolvimento de perovskitas ferroelétricas capazes de absorver a luz visível, particularmente KBNNO - [KNbO3]0,9[BaNi0,5Nb0,5O3-δ]0,1 (band-gap Eg= 1,39 eV), tem encorajado a aplicação desses materiais na camada ativa de células solares. Em dispositivos fotovoltaicos, esses materiais podem permitir a obtenção de voltagens superiores à ma
Cerâmica. Publicado em: 2019-01
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3. Piezoelectricity from Elastic and Dielectric Measurements on Unpoled Ferroelectrics
A method is described to assess the piezoelectric response of ferroelectric materials from the temperature dependence of the elastic moduli and dielectric constant of unpoled samples. The limits and advantages over the traditional methods on poled samples are discussed. A quantitative check is made by comparing the piezoelectric softening measured below the
Mat. Res.. Publicado em: 07/06/2018
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4. Ba-DOPED ZnO MATERIALS: A DFT SIMULATION TO INVESTIGATE THE DOPING EFFECT ON FERROELECTRICITY
ZnO is a semiconductor material largely employed in the development of several electronic and optical devices due to its unique electronic, optical, piezo-, ferroelectric and structural properties. This study evaluates the properties of Ba-doped wurtzite-ZnO using quantum mechanical simulations based on the Density Functional Theory (DFT) allied to hybrid fu
Quím. Nova. Publicado em: 2016-04
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5. Crystallization of II-VI semiconductor compounds forming long microcrystalline linear assemblies
In this work we report the formation of long microcrystalline linear self-assemblies observed during the thin film growth of several II-VI compounds. Polycrystalline CdTe, CdS, CdCO3, and nanocrystalline CdTe:Al thin films were prepared on glass substrates by different deposition techniques. In order to observe these crystalline formations in the polycrystal
Mat. Res.. Publicado em: 01/02/2013
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6. Aplicação de novos materiais em transistores de efeito de campo ferroelétricos
In this work, we investigated the electrical properties of the polyelectrolyte PSS in its sodium form (PSS-Na, Polystyrene sulfonic in the sodium form) and acid form (PSS-H, polystyrene sulfonic in the acid form) and also doped with Fe3+ for application in Ferroelectric Field Effect Transistors (Fe-FET). The PSS-Na was acquired from Aldrich and PSS-H was obt
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/07/2012
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7. Preparação e Caracterização de Pós e Filmes De PbTiO3 obtidos pelo Método Pechini / Preparation and Characterization of Powders and Films From PbTiO3 obtained by Pechini method
Non-crystalline materials, commonly referred to as amorphous materials have attracted great interest in engineering and technology. This is due mainly to its photoluminescent properties at room temperature around 25 C. The aim of this study was the Pechini method in order to obtain ceramic powders and amorphous films of amorphous lead titanate. The lead tita
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 29/02/2012
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8. Effect of pH-induced nanopowder deagglomeration on sintering, microstructure and dielectric properties of Ba0.77Ca0.23TiO3 ceramics
Ba0.77Ca0.23TiO3 ceramics were produced in this work starting from nanopowders synthesized via a polymeric precursor method. By adjusting the pH values of the precursor solutions above 7, it was possible to prepare powders weakly aggregated and with a smaller particle size, both facts which traduced into an enhanced nanopowders' sintering process at comparat
Materials Research. Publicado em: 17/07/2012
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9. Domínios ferroelétricos em cerâmicas e materiais nanoestruturados: investigação por microscopia de piezoresposta
In this work, ferroelectric domain structure was investigated by Piezoresponse Force Microscopy (PFM). To this, an Atomic Force Microscope (AFM) has been modified to use it as PFM at room temperature and at high temperatures. Ferroelectric ceramics were used in the as bulk ceramic samples of Pb(Zr0,40Ti0,60)O3 (PZT 40/60) and (Pb0,79La0,21)TiO3 (PLT 21) prod
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 07/12/2011
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10. Estudo das transiÃÃes de fase do RbBi0,31 3Nd0,02 W8/3O9, submetido a variaÃÃes de pressÃo hidrostÃtica e temperatura. / Studies of phase transitions of RbBi0,313Nd0,02W8/3O9 submit variation of hydrostatic pressure en temperature
Tungsten bronzes has attracted great attention owing to it is interesting physical properties. Hexagonal tungsten of the form AxWO3 (with A = K, Rb, Cs), are well know superconductors. The RbBi1/3W8/3O9 (RBW) material, belongs to the valence balanced hexagonal tungsten materials with ABxW3-xO9 stoichiometry (with A = Cs, K, Rb, Tl, and B = Bi, Nd, Ta, Zr, Sc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 16/02/2009
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11. Cation size effects-modified phase and PTCR development in Er3+ and Ca2+ co-doped BaTiO3 ceramics during sintering
Development of the positive temperature coefficient of resistivity (PTCR) in Er3+ and Ca2+ co-doped ferroelectric BaTiO3 was studied in this work, with Er3+ being used to act as a donor doping. Irrespective of all the materials showing high densities after sintering at 1200 to 1300 ºC, these revealed insulator at the lowest sintering temperature, changing t
Materials Research. Publicado em: 2009-09
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12. Preparação e caracterização de materiais ferroelétricos de composição Bi4Ti3O12 contendo Lantânio e Érbio / Synthesis and characterization of Bi4Ti3O12 ferroelectric materials containing Lanthanum and Erbium
This work describes a systematic study of the influence of the lanthanum atom addition in the Bi4Ti3O12 (BIT) phase and the erbium atom addition in the Bi3,25La0,75Ti3O12 (BLT075) phase in terms of their synthesis process and its structural, microstructural and electrical properties. Ceramics of nominal composition Bi4-xLaxTi3O12 (BLTx) with 0 x 2 mol% and B
Publicado em: 2009