Wyniki wyszukiwania - Biblioteka Nauki

1

Tl-based superconducting films prepared by aerosol spray deposition and thallinated in an open system

100%

Matkovičová Z. , Štrbík V. , Plesch G. , Valeriánová M. , Dujavová A.

Open Physics

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2007

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tom 5

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nr 3

398-404

EN

Superconducting Tl-based films were prepared on a LaAlO3 single crystal substrate. Spray pyrolysis of Ba, Ca and Cu nitrate solutions was used for deposition of the precursor films. They were subsequently ex-situ thallinated in flowing oxygen (open system). While the superconducting Tl-2212 phase formed at an annealing temperature of 880°C, thallination at 900°C led to the formation of a Tl-2223 /Tl-2212 mixture. The amount of Tl-2223 increased with prolonged thallination, whereas the Tl-2212 phase progressively disappeared. Films prepared in such a manner were c-oriented and contained only low amounts of non-superconducting impurities. The resulting samples were characterized by XRD and SEM and their T C values were determined by resistive four-point measurements. They showed critical temperatures in the range of T ON = 125–135 K, T C0 = 91–93 K. Differences between the composition and properties of the obtained films and those thallinated in closed systems under 50 kPa of oxygen are discussed in this paper. Results show that the Tl-2212 → Tl-2223 transformation proceeds at a slower rate under flowing oxygen than in a closed system.

2

Optical characterization of the CdZn(S1-x Sex )2 thin films deposited by spray pyrolysis method

100%

Ilican S. , Zor M. , Caglar Y. , Caglar M.

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2006

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tom Vol. 36, nr 1

29-37

EN

CdZn(S1-xSex )2 thin films have been deposited onto glass substrates by the spray pyrolysis method at a 275°C substrate temperature. The average optical transmittance of all the films was over 65% in the wavelength range 450-800 nm. The optical absorption studies reveal that the transition is direct with band gap energy values between 2.47-3.04 eV. The optical constants such as refractive index, extinction coefficient and dielectric constants have been calculated for these films. The dispersion parameters such as Eo (single-oscillator energy) and Ed (dispersive energy) have been discussed in terms of the Wemple-DiDomenico single-oscillator model. The values obtained by this method are suitable for many scientific studies and technological applications, such as gas sensors, heat mirrors, transparent electrodes, solar cells and piezoelectric devices.

3

The influence of glass surface preparation on electrical and optical properties of SnO2 thin films obtained by spray pyrolysis technique

100%

Nocuń M. , Pająk Z.

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2008

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tom Vol. 38, nr 1

181-187

EN

SnO2 conducting thin films were prepared by spray pyrolysis. Glass surface was prepared by etching in HF and acetic acid solutions. Sodium barrier coatings with different compositions were prepared by the sol-gel technique. The influence of the glass surface preparation on optical properties of SnO2 was studied using reflectance spectroscopy. XPS was used as a tool to evaluate barrier properties of the coating. The morphology of the thin layer was studied by a scanning electron microscope. The results have shown that the titanium containing coating has the best sodium diffusion barrier property. The conductivity of SnO2 film strongly depends on the glass surface preparation. The lowest conductivity was measured for clean glass but the highest for alumina containing barrier coating.

4

Oxide layers fabricated by spray pyrolysis on metallic surfaces

75%

Kobierowska K. , Karpińska M. , Molin S. , Jasiński P.

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2012

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tom Vol. 53, nr 1

74-76

EN

In this paper the possibilities of using spray pyrolysis method to produce yttrium stabilized zircoma layers have been examined. A stainless steel, type 316L, was used as a substrate. It was important to determine the optimal conditions of the films preparation. The basic parameter in the pyrolysis technology process is a surface temperature, which was systematically examined. The layer was intended to be used as protective film for metallic implants. In order to determine the corrosion resistance and protective properties of produced layers, potentiodynamic measurements in mimicking tissue environment solution were carried out. It provided information about the corrosive effects, which occur on the steel surface and on the protective layer. The experimental results showed that improvement of corrosion resistance properties was obtained by spraying the precursor at 390°C.

PL

W niniejszym artykule przebadane zostały możliwości zastosowania meetody pirolizy aerozolowej do wytwarzania warstw z tlenku cyrkonu stabilizowanego itrem na podłożu ze stali nierdzewnej 316L. W pierwszej kolejności bardzo ważne było określenie optymalnych warunków przygotowania warstw. Podstawowym parametrem w procesie napylania warstw metodą pirolizy aerozolowej jest temperatura powierzchni, której wpływ systematycznie przebadano. Przeprowadzone badania wykazały przydatność warstw z zastosowaniem tlenku cyrkonu stabilizowanego itrem wytworzonych metodą pirolizy aerozolowej. W celu określenia odporności na korozję oraz właściwości ochronnych zostały przeprowadzone pomiary potencjodynamiczne w roztworze imitującym środowisko tkankowe. Wyniki uzyskane z pomiarów laboratoryjnych dostarczyły informacji na temat zjawisk korozyjnych zachodzących na powierzchni stali oraz warstw ochronnych. Badania pokazały, że warstwą wykazującą poprawę właściwości antykorozyjnych jest ta, która powstała poprzez napylenie prekursora polimerowego w temperaturze 390°C.

5

Drying Behaviour of ZrOCl2 Solution Droplet in ZrO2 Fine Particles Production by Spray Pyrolysis

75%

Kobayashi J. , Itaya Y. , Matsuda H. , Hasatani M.

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2000

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tom Vol. 48, nr 3

383-397

EN

The difference of the mechanism to yield either dense or hollow particles may be caused rather at the stage prior to decomposition in the sequential steps because any structural change is not possible except for stress-induced strain and crack once a solid is formed. The stage of solidification and drying of the droplets plays an important role to determine the structure of the final particles in SPM. In this paper, the drying behaviour of atomized droplets of zirconium oxychloride solution is discussed in comparison between the experimental result and theortical analysis. The drying behaviour of the droplets with contraction is simulated assuming uniform temperature and concentration in droplets and surface evaporation. The hollow particles more than [formula] are experimentally observed in the obtained particles for any conditions. Drying of the atomized droplets is predicted to complete in 20-50 msec from atomizing into the reactor by theoretical analysis and the drying rate is very large. Because of the large drying rate, the concentration distribution in the droplet is formed so that the shell on the droplet surface is formed. The shell on the droplet surface is often broken by the vapour pressure and/or thermal stress with a rise in temperature. Hence the hollow spheres and the small fragments are yielded.