Wyszukiwarka
dr hab. inż. Jakub Karczewski
Zatrudnienie
- Dyrektor Instyt. Nanotechnologii i Inżyn. Materiał w Instytut Nanotechnologii i Inżynierii Materiałowej
- Profesor uczelni w Instytut Nanotechnologii i Inżynierii Materiałowej
Publikacje
Filtry
wszystkich: 242
Katalog Publikacji
Rok 2015
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Tin oxide nanoparticles from laser ablation encapsulated in a carbonaceous matrix – a negative electrode in lithium-ion battery applications
PublikacjaThis report concerns carbonaceous electrodes doped with tin(II) oxide nanoparticles. Tin nanoparticles are obtained by pulsed laser ablation in water. Crystalline nanoparticles have been encapsulated in a carbonaceous matrix formed after pyrolysis of a mixture consisting of tin/tin(IV) oxide nanoparticles and gelatine. The obtained material is characterized by means of X-ray diffraction, selected area diffraction, scanning electron...
Rok 2014
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Aggregation of Rhodamine 6G in titanium dioxide nanolayers and bulk xerogels
PublikacjaNanolayers and bulk xerogels of Rhodamine 6G (Rh6G) in titanium dioxide (Rh6G/TiO2) were prepared using the sol–gel method. The spectroscopic and structural properties of these two types of hybrid matrices were studied as a function of dye concentration. In both cases absorption, fluorescence and time resolved emission spectra show the formation of fluorescent aggregates. The observed stronger changes in characteristics of bulk...
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Correlation between structural and electrical properties in highly porous (Y,Sr)(Ti,Nb)O3-delta SOFC anodes
PublikacjaIn order to find a relationship between structural and electrical properties, niobium and yttrium doped SrTiO3 ceramics were prepared via solid-state reaction. The samples were sintered in hydrogen and air conditions. The samples were also fabricated with a pore-former to obtain highly porous specimens. The electrical properties of Nb-doped SrTiO3 samples and yttrium and niobium co-doped SrTiO3 were compared. The comparable electrical...
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Electrical properties and structure of lead-borate glass containing iron ions.
PublikacjaThe ac and dc conductivity in iron–lead-borate glass samples was investigated in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by the means of atomic force microscopy (AFM) and the crystalline phases (if present) were identified by the means of X-ray diffractometry. Two types of ac electrical behaviour were observed. The first group of glass samples which...
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Electronic conductivity in the SiO2-PbO-Fe2O3 glass containing magnetic nanostructures
PublikacjaThe linear impedance spectra of iron–silicate–lead glass samples were measured in the frequency range from 1 MHz to 1 MHz and in the temperature range from 153 K to 423 K. The structure was investigated by means of XRD and atomic force microscopy. Local electrical and magnetic properties of the samples were tested with the aid of electrostatic force microscopy (EFM) and magnetic force microscopy (MFM). The obtained results show...
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Impedance Studies of Phosphate-iron Glasses Containing Niobium and Titanium
PublikacjaThe ac and dc conductivity in phosphate-iron-niobate glasses with addition of titanium oxide was investigated as a function of temperature and frequency with the use of impedance spectroscopy. The topography and microstructure of glasses were investigated by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and confocal microscopy methods. The obtained results show that all samples are amorphous but they...
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Microstructure and Dielectric Properties of Barium-vanadate Glasses
PublikacjaThe ac and dc conductivity in barium-vanadate glasses was investigated as a function of temperature and frequency with the use of impedance spectroscopy. The topography and microstructure of glasses were investigated by the means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) methods. The XRD results show that all samples are amorphous but microscopy investigation reveals that glasses with greater amount of V2O5...
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Nanostructure and dielectric behavior of vanadate glasses containing BaTiO3
PublikacjaThe ac and dc electrical conductivity of barium titanate doped bismuth-vanadate as-quenched and heat-treated materials was measured in the frequency range from 1 mHz to 1 MHz and in the temperature range from 153 K to 423 K with the impedance spectroscopy method. The microstructure was investigated by means of XRD, scanning electron microscopy (SEM), atomic force microscopy (AFM) and confocal microscopy. The obtained results showed...
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Novel Functionalization of Boron-Doped Diamond by Microwave Pulsed-Plasma Polymerized Allylamine Film
PublikacjaWe report the novel modification of a hydrogen-terminated polycrystalline boron-doped electrode with a microwave pulsed-plasma polymerized allylamine. Boron-doped diamond (BDD) was coated with a very thin layer of adherent cross-linked, pinhole- and additive-free allylamine plasma polymer (PPAAm) resistant to hydrolysis and delamination and characterized by a high density of positively charged amino groups. The pulsed microwave...
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Phase Separation and Electrical Properties of Manganese Borosilicate Glasses
PublikacjaThe structure and electrical properties of manganese borosilicate glasses of a composition of xMnO-(0.8-x)SiO2-(0.2)B2O3 (x=0.4, 0.5 and 0.6 in mol) were investigated by impedance spectroscopy, SEM, XRD and confocal microscopy methods. The influence of composition on the glass structure and electrical properties was discussed. A separation of two amorphous phases was observed and it was concluded that one phase is SiO2-rich and...
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The properties of reduced Bi-Ge-O glasses for thermoelectric devices
PublikacjaThe bismuth-germanate glasses have been investigated to examine their applicability for thermoelectric devices. In order to increase their electrical conductivity, the 25Bi2O3–75GeO2 glass samples have been reduced at 340-380°C for 10 hours in hydrogen. It has been shown that such heat treatment in H2 leads to the reduction of metal ions Bi3+ and Ge4+ into neutral atoms and the formation of metal grains both in an amorphous glass...
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The properties of reduced Ge-Sb-O glasses for thermoelectric devices
PublikacjaThe structural and electrical properties of germanium-antimonate glasses after heat treatment in hydrogen have been determined. In the case of 50GeO2-50Sb2O3 glass reduced at 340°C even for less than 1 hour a continuous layer of antimony granules is formed and its electrical properties determine the surface conductivity of the reduced sample. The bulk electrical conductivity at 100°C of this sample was determined as 1000 Scm-1...
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Thickness and structure change of titanium (IV) oxide thin films synthesized by the sol–gel spin coating method
PublikacjaTitanium dioxide is a well-known material in nanotechnology, while it provides new opportunities due to its interesting properties, for example, as a semiconductor with a quite significant forbidden band gap energy of 3.2 eV. In this study, thin films of titanium dioxide (TiO2) were synthesized in amorphous and crystallographic systems using the sol–gel process. Atomic Force Microscopy (AFM), Raman spectroscopy and X-ray diffraction...
Rok 2013
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Application of wet powder spraying for anode supported solid oxide fuel cell with a perowskite SrTi0.98Nb0.02O3-d anode
PublikacjaAnode-supported solid oxide fuel cell with SrTi0.98Nb0.02O3–d anode, yttria-stabilized zirconia electrolyte and La(Ni0.6Fe0.4) O3d cathode has been successfully fabricated and evaluated. Process of anode support fabrication has been presented. Wet powder spraying and high temperature sintering method have been studied and applied to deposit the thin electrolyte layer.In order to improve catalytic properties of the anode, it has...
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CGO FILMS ON YSZ ELECTROLYTE FABRICATED BY SPRAY PYROLYSIS FOR SOFC
PublikacjaINTRODUCTION Solid oxide fuel cells are one of the fastest developing energy converters. The advancement introduced by research community provides steady state progress is stability and performance of the fuel cells. Significant influence on the cell’s performance and stability is related to cell design. The simplest design just consists of an anode, a solid electrolyte and a cathode. However, in order to improve the properties,...
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Fabrication, Microstructure and High Temperature Corrosion Resistance of Porous Alloys for Solid Oxide Fuel Cells
PublikacjaPorous alloys find use in modern Solid Oxide Fuel Cells as the supporting structures. As they are exposed to high temperatures (> 500°C) an oxide scale forms on their surface due to high temperature corrosion phenomena. Since the ratio between the surface area and volume is much higher than for planar samples, formation of the oxide can lead to a breakaway oxidation after relatively short times. Therefore corrosion properties of...
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Influence of synthesis conditions on zinc oxide nanorode layer morphology
PublikacjaIn recent years one dimensional (1D) nanostructures (nanotubes, nanowires, nanoribbons and nanorods) have been widely studied. Among studied nano-materials, the greatest interest can be seen for zinc oxide (ZnO). However, there is still a need for simple, inexpensive and reproducible fabrication method. In the literature different fabrication methods can be found, most of them requires expensive equipment and involve complex...
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Interactions between components of SrTi0.98 Nb0.02O3-δ-YSZ and SrTi0.98 Nb0.02O3-δ -CeO2 composites
PublikacjaComposites consisting of SrTiO3-based perovskite and either yttria-stabilized zirconia or ceria were investigated. The mechanical compatibility and possible inter-diffusion between phases were characterized by scanning electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. A gradual disappearance of Ce-containing phases with an increase in the temperature of reduction in hydrogen was noticed. Moreover,...
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Investigation methods of ionic conductivity measurements in polycrystalline MIEC (mixed ionic-electronic conductor) based on perovskite ceramics
PublikacjaPaper about the measurements of ionic conductivity in LSM and strontium titanate ceramics.
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Investigation of functional layers of solid oxide fuel cell anodes for synthetic biogas reforming
PublikacjaSolid oxide fuel cells (SOFCs) are one of the most promising energy conversion devices due to their high efficiency, low pollution and fuel flexibility. Unfortunately, when hydrocarbons are used as a fuel, for example in the form of a biogas, solid carbon can deposit on the anode surface. This process leads to the degradation of the fuel cell performance. A possible solution to this problem is to apply an additional catalytic material,...
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YSZ Thin film deposited on porous substrate by spray pyrolysis
PublikacjaIn this work the results of deposition of YSZ layer on a porous substrate using an ultrasonic Spray Pyrolysis are presented.
Rok 2012
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Badanie przewodnictwa jonowego materiału katodowego do ogniw SOFC na bazie La1-xSrxMnO3-δ
PublikacjaMieszane przewodniki jonowo-elektronowe na bazie domieszkowanego manganianu lantanu znajdują powszechne zastosowanie m.in. jako elektrody w ogniwach paliwowych, czujnikach gazów lub jako warystory. Jednak wciąż niepoznane do końca mechanizmy występowania zjawiska mieszanego przewodnictwa sprawiają, że prace nad tymi materiałami wciąż trwają. Określenie składowej jonowej tego typu materiałów perowskitowych wymaga zastosowania...
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublikacjaNonstoichiometric Nb-substituted SrTiO3 compounds were investigated in order to discuss the influence of nonstoichiometry at the sample properties in the light of recent results reported in the literature. Structural and electrical properties of samples were characterized. Investigated compounds were also applied as anodes for Solid Oxide Fuel Cells and their reactivity with YSZ electrolyte was examined. The defect chemistry explaining...
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Donor-substituted SrTi1+xO3−δ anodes for SOFC
PublikacjaPrzebadano wpływ niestechiometrii na właściwości tytanianu strontu domieszkowanego niobem. Zaproponowano chemię defektów dla tego typu związków.
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Evaluation of porous ferritic Fe22Cr stainless steel for solid oxide fuel cells at high temperature
PublikacjaW pracy przedstawiono wyniki badań korozji stali Fe22Cr w wysokich temperaturach.
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Ferromagnetic nanocrystallites in the SiO2 - PbO - Fe2O3 glass system
PublikacjaThe structure of 50% SiO2 - 35% PbO - 15% Fe2O3, 50% SiO2 - 30% PbO - 20% Fe2O3 and 50% SiO2 - 25% PbO - 25% Fe2O3 (in mol%) glass was investigated by the means of AFM microscopy and X-ray diffraction. Observation by the atomic force microscopy shows that each of prepared iron oxide glass doesn't have homogeneous structure and some nanocrystallites were detected. Next, test with neodymium magnet found out strong magnetic properties...
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaTo further understand the suitability of Ni-Cr-base alloy for solid oxide fuel cell (SOFC), a commercial Ni-Cr-Fe-Mo alloy, Hastelloy X was selected and evaluated for oxidation behaviour under high temperature conditions. HastelloyX was chosen due to its unusual resistance to oxidizing, reducing and neutral atmospheres. For long term stability of metal supported fuel cell, the corrosion resistance plays a vital role and must be...
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High temperature corrosion resistance of porous hastelloy alloy
PublikacjaW pracy przedstawiono badania korozyjne stopu Hastelloy w wysokich temperaturach.
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3 perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Microstructural and electrical properties of Y0:07Sr0:93−xTiO3− perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontium titanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work. It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent. Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry. The...
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Microstructural and electrical properties of Y0.07Sr0.93-xTiO3-δ perovskite ceramics
PublikacjaIn order to find a relationship between electrical and microstructural properties, yttrium-doped strontiumtitanate (7 mol%) with various values of strontium nonstoichiometry was investigated and shown in this work.It has been observed that yttrium doping can affect the electrical properties of SrTiO3 to a great extent.Moreover, the microstructural and electrical properties can be influenced by strontium nonstoichiometry.The defect...
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Solid Oxide Fuel Cells with Ni infiltrated perovskite anode
PublikacjaNiobium-doped strontium titanate was used as the anode for a solid oxide fuel cell. Electrolyte-supported cells were prepared with pure perovskite and composite perovskite–yttria–stabilized-zirconia (YSZ) anodes. Fuel cell tests demonstrated significant improvement in power density after infiltration with a small amount of Ni. The obtained values of power densities are comparable with conventional Ni/YSZ cermet anode. In addition,...
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Solid oxide fuel cells with Ni-infiltrated perovskite anode
PublikacjaWytworzono próbki na bazie tytanianu strontu domieszkowanego niobem i przebadano wpływ nasączania niklem na właściwości tych materiałów.
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The comparison of SrTi0.98Nb0.02O3-δ-CeO2 and SrTi0.98Nb0.02O3-δ-YSZ composites for use in SOFC anodes
PublikacjaWytworzono i przebadano właściwości strukturalne i elektryczne kompozytów SrTi0.98Nb0.02O3-δ-CeO2 i SrTi0.98Nb0.02O3-δ-YSZ. Przeprowadzono testy materiałów zastosowanych jako anody w tlenkowych ogniwach paliwowych.
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The comparison of SrTi0.98Nb0.02O3–δ-CeO2 and SrTi0.98Nb0.02O3–δ-YSZ composites for use in SOFC anodes
PublikacjaComposites of Nb-doped strontium titanate mixed with yttria-stabilized zirconia or cerium oxide in 50:50, 70:30 and 85:15 weight ratios were evaluated as possible anode/electrolyte interface materials for solid oxide fuel cells in terms of chemical compatibility, electrical conductivity and mechanical properties. It has been shown that composite samples prepared by typical powder-mixing methods remain single-phase up to 1400°C....
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Właściwości strukturalne i katalityczne domieszkowanych związków typu SrTi(1-x)Fe(x)O3
PublikacjaPublikacja naukowa opisująca wytwarzanie i badanie właściwości strukturalnych i katalitycznych domieszkowanego itrem i żelazem tytanianu strontu.
Rok 2011
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Badanie ogniwa paliwowego typu SORC z anodą na bazie perowskitu SrTi03
PublikacjaPublikacja naukowa opisująca budowę i badanie ogniwa paliwowego typu SOFC zbudowanego na elektrolicie z zastosowaniem anody na bazie domieszkowanego donorowo tytanianu strontu.
Rok 2010
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Electrical and structural properties of Nb-doped SrTiO3
PublikacjaNiobium-doped strontium titanate synthesized via conventional solid-state reaction has been studied. Influence of niobium content on the lattice parameters and electrical conductivity has been reported. Various reduction conditions have been investigated. For samples reduced in hydrogen at 1400°C, a transition from thermally activated to metallic behavior has been observed. Maximum electrical conductivity (ca. 55 Scm−1 at 650°C)...
Rok 2009
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Electrical and structural properties of Nb-doped SrTiO3 ceramics
PublikacjaPrzebadano wpływ zawartości niobu na strukturę i własności elektryczne tytanianu strontu. Zbadany został wpływ warunków redukcji i porowatości na właściwości materiału. Za optymalne uznano domieszkowanie niobem w wysokości 2% molowych.
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Electrical properties of Y0.08Sr0.92Ti0.92Nb0.08O3_−delta after reduction in different reducing conditions
PublikacjaPraca przedstawia badania właściwości elektrycznych perowskitów Y0.08Sr0.92Ti0.92Nb0.08O3−ı redukowanych w różnych warunkach termicznych. Obserwowano wysoką przewodność elektryczną próbek redukowanych w atmosferze amoniaku. Przewodność Y0.08Sr0.92Ti0.92Nb0.08O3−ı redukowanego w amoniaku w 1500 ◦C była rzędu 600 S/cm w 200 ◦C. Przewodność elektryczna próbek redukowanych w amoniaku w 1500 ◦C była stabilna zarówno w atmosferze wodoru...
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Electrical properties of Y0.08Sr0.92Ti0.92Nb0.08O3-δ after reduction in different reducing conditions
PublikacjaElectrical properties of perovskite Y0.08Sr0.92Ti0.92Nb0.08O3−ı after reduction in different conditions were studied. Relatively high electrical conductivity in samples reduced in ammonia was observed. The conductivity of Y0.08Sr0.92Ti0.92Nb0.08O3−ı reduced in ammonia at 1500 ◦C was of about 600 S/cm at 200 ◦C. Conductivity after reduction in ammonia at 1500 ◦C was stable both in hydrogen and oxygen atmosphere up to 600 ◦C. Reduction...
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The influence of preparing conditions on the properties of SrTi0.98Nb0.02O3-YSZ composite
PublikacjaZbadano wpływ warunków przygotowania na właściwości kompozytów SrTi0.98Nb0.02O3-YSZ jako potencjalnych warstw przejściowych między anodą a elektrolitem w tlenkowych ogniwach paliwowych SOFC. Udowodniono, że proces wstępnej obróbki temperaturowej substratów oraz sposób ich mielenia znacznie wpływa na przewodnictwo elektryczne badanych materiałów.
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