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EN
In the present study, the lead-free BaTi1-x Zrx O3 (for x = 0, 0.05 and 0.15) ceramics were prepared by High-Energy Ball Milling and heat treatments. The performed X-ray, SEM and EDS measurements confirmed high purity, good quality and the expected quantitative composition of the obtained samples. The study of dielectric properties was performed by means of broadband dielectric spectroscopy at the frequency ranging from 0.1 Hz to 10 MHz. The obtained measurement data, analyzed in accordance with the Arrhenius formalism demonstrated the presence of relaxation type dielectric mechanisms. The impedance answer of studied ceramic materials indicated the presence of two relaxation processes: one with a dominant resistive component and the other with a small capacitive component. The observed dielectric relaxation process is temperature dependent and has a “non-Debye” character.
EN
Polycrystalline samples BaTiO3 and the solid solutions Ba0.9 Sr0.1 TiO3, 0.9 Sr0.1 Ti0.9 Sn0.1 O3, Ba0.9 Sr0.1 Ti0.8 Sn0.2 O3 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 and morphology of the investigated samples were characterized by an X-ray diffraction (XRD) and scanning electron microscopy (SEM). The characterization of electrical properties of the ceramics within the temperature range from –130°C to 250°C were performed by means of a dielectric spectroscopy method at the frequency ranging from 0.1 Hz to10 MHz. The diffusion of the paraelectric – ferroelectric phase transition and dielectric relaxation for ceramic samples are described.
3
Content available remote Właściwości dielektryczne materiałów ceramicznych otrzymanych na bazie TiO2
PL
Domieszkowane jonami donorowymi (Nb5+, V5+) i akceptorowymi (In3+) próbki TiO2 (rutyl) otrzymano konwencjonalną metodą reakcji w stanie stałym. Strukturę badanych próbek scharakteryzowano przy pomocy analizy XRD. Właściwości dielektryczne próbek zbadano w zakresie temperatur od -100 stopni C do 200 stopni C przy pomocy szerokopasmowej spektroskopii dielektrycznej w zakresie częstotliwości pola elektrycznego od 0,1 Hz do 10 MHz. Analiza zależności temperaturowych przenikalności dielektrycznej, przewodnictwa i modułu elektrycznego dostarczyła nowych informacji na temat właściwości fizycznych badanych materiałów ceramicznych.
EN
Doped with donor (Nb5+, V5+) and acceptor (In3+) ions TiO2 (rutile) was obtained by the conventional solid state reaction method. The structure of the investigated samples was characterised by X-ray diffraction (XRD). The dielectric properties of the samples at the temperature ranging from -100 C to 200 C was studied by means of the broadband dielectric spectroscopy method at the frequency ranging from 0,1 Hz to 10 MHz. An analysis of the temperature dependences of dielectric permittivity, electric modulus and conductivity provided new details about the physical properties of the ceramic samples.
EN
The paper presents a simple way to improve the photocatalytic properties of titanium dioxide using mechanochemical method. The TiO2 (Anatase) powders was subjected to high-energy ball milling in dry environment and in methanol. It has been shown that it is possible to induce the phase transformation from Anatase to Rutile and produce a material with a higher photocatalytic activity in the UV light. Physicochemical characteristics of the products were based on the following methods and techniques: X-ray powder diffraction (XRD), IR and UV-Vis (DR) spectroscopy, measurements of specific surface area (BET). The photocatalytic activity of the powders was measured in the decomposition reaction of methyl orange in water.
EN
The study shows the advisability of using a mechanochemical synthesis method, based on a high-energy planetary ball milling, to a modification of barium titanate by a vanadium doping. This method improves useful properties of BaTi0:95V0:05O3 as a capacitor material. It has a high value of electric permittivity e' in the wide range of temperature and low dielectric losses e" as well as a low electrical conductivity.
EN
This paper presents mechanochemical synthesis as an alternative to the traditional high-temperature synthesis of advanced electrotechnical ceramic materials with a perovskite-type structure. The reaction conditions for high-energy ball milling, e.g. reaction environment, energy of milling and additives to BaTiO3 such as metallic iron or zirconia from the exfoliation of the milling vessel and grinding media are discussed.
PL
W artykule przedstawiono mechanochemiczną syntezę jako alternatywną w stosunku do tradycyjnych, wysokotemperaturowych metod wytwarzania zaawansowanych ceramicznych materiałów elektrotechnicznych o strukturze perowskitu. Wykazano, iż mechanochemiczna synteza jest również skuteczną metodą modyfikacji właściwości BaTiO3 poprzez substytucyjne podstawienie obcych jonów. Określono również właściwości otrzymanych roztworów stałych.
EN
This paper considers mechanochemical synthesis as an alternative to the conventional, hightemperature method of manufacturing advanced electrical ceramic materials with a perovskite structure. Mechanochemical synthesis is also presented as an effective method for modifying the properties of BaTiO3 by substitution of foreign ions, and the effect of such substitution on the properties of the solid solutions is also discussed.
9
Content available remote A novel class of dispersants for colloidal processing of hydroxyapatite
EN
Poly(acrylic acid) (PAA) polymer modified with poly(ethylene glycol) (PEG) was used as a dispersant in preparation of hydroxyapatite aqueous suspension. The effect of dispersant structure on suspension stabilization was investigated through the studies of physicochemical properties of the obtained dispersions. Novel dispersants and HAp suspensions were characterized using pH and viscosity measurements.
PL
Poli(kwas akrylowy) (PAA) modyfikowany poli(glikolem etylenowym) (PEG) zastosowano jako dyspergator wodnej suspensji hydroksyapatytowej. Określono wpływ struktury dyspergatora na stabilność suspensji na podstawie badań właściwości fizykochemicznych otrzymanych dyspersji. Nowoczesne dyspersanty i zawiesiny HAp scharakteryzowano z zastosowaniem pomiarów pH i lepkości.
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