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Structural analysis of Srn+1RunO3n+1 thin films deposited by laser ablation

Chmielowski R., Madigou V., Fremy M. A., Blicharski M., Nihoul G.

Archives of Metallurgy and Materials

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2006

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Vol. 51, iss. 1

83-86

EN

The series of conductive oxides, Srn + 1RunO3n+1, has been studied for applications in microelectronics as these oxides could be interesting electrode materials for ferroelectric memories (FeRAM). Sr2RuO4 seems to be an interesting candidate. Thin films of Sr2RuO4 were obtained by pulsed laser deposition on a Si (001) substrate. The influence of deposition times and pulse frequencies on the microstructure and properties of the deposited thin films was analysed. Thin films characterization was done by X-ray diffraction, EDS microanalysis, scanning electron microscopy, high-resolution transmission electron microscopy and conductivity measurements. Most of the films are composed of several oxides of the Srn + 1RunO3n+1 series. However, their surface is well-defined and, for some films, the conductivity is interesting for applications. Deposition parameters have strong influence on composition and microstructure of oxides films.

PL

Badania struktury krystalicznej, mikrostruktury oraz własności elektrycznych cienkich warstw, które maja mieć zastosowanie jako elektrody w pamięciach ferroelektrycznych (FeRAM) skupiają się na materiałach tlenkowych. Jednym z nich jest Sr2RuO4 należący do grupy tlenków Srn + 1RunO3n+1, charakteryzujących się dobrymi własnościami elektrycznymi. Cienkie warstwy z Sr2RuO4 osadzono techniką ablacji laserowej na płaszczyźnie (001) monokryształu krzemu. Analizowano wpływ czasu ekspozycji oraz częstotliwości impulsów laserowych na strukturę i własności otrzymanych warstw. Badania prowadzono z wykorzystaniem, rentgenowskiej dyfrakcyjnej analizy fazowej, mikroanalizatora EDS oraz za pomocą skaningowej mikroskopii elektronowej i transmisyjnej mikroskopii elektronowej. Przeprowadzone badania własności elektrycznych wykazały przydatność cienkich warstw do zastosowań na elektrody w układach mikroelektronicznych.

2

Nanoparticles of cerium dioxides for gas sensor applications.

Villain S., Leroux C., Musso J., Fremy M.A., Pischedda M.H., Gavarri J.R.

Inżynieria Materiałowa

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2001

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R. XXII, nr 5

935-938

EN

The aim of this work is to elaborate nanostructured cerium dioxides for catalytic and gas sensor applications. Nanosized cerium oxide powders were prepared via three chemical routes: 1) chemical precipitation followed by high-energy mechanical milling; 2) soft chemical preparation, 3) an unusual method of pulverization of liquid solution developed in our laboratory. The obtained powders were characterized using X-Ray diffraction analyses and Transmission Electron Microscopy experiments. Nanoparticles of pure CeO2 oxide having their sizes ranging from 2 to 10 nanometers have been obtained.

3

Sintering effects in superconductor/ferrite composites.

Kopia-Zastawa A., Suliga I., Fremy M.A., Pischedda M.H., Gavarri J.R., Jasieńska S.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

876-879

EN

Granular superconductor/ferrite composites have been fabricated using various sintering conditions such as: volume fraction, sintering temperature and sintering time. The superconducting phase is the well known Bi (Pb)-2223 phase with Tc=110K. The ferrite is NiFe2O4. Using magnetic measurements, X-ray diffraction, scanning electron microscopy and susceptibility measurements the composites after sintering have been characterized.

4

Microstructure, transport properties and chemical reactions in ceramics and composities: application to superconductor based composites.

Gavarii J.R., Kopia-Zastawa A., Fremy M.A., Pischedda M.H., Suliga I., Jasieńska S.

Inżynieria Materiałowa

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1998

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R. XIX, nr 4

813-818

EN

In this review, we deal with active two-phase composites made of one superconducting constituent (S) and of an additional phase (F) having a mechanical or electrical role. To interpret the effects of sintering processes, two types of modelling approaches are discussed: firstly, the modelling of the chemical diffusions and, secondly, the chemical reactivity which conditions both electrical and mechanical properties of the resulting F/S composites. The chemical reactions at the interfaces of the F/S composites are firstly described by a simplified Fick law approach: each element can be characterized by one apparent chemical diffusion coefficient D. Then expressing the chemical reaction following the classical form: F + n.S -> P, and considering elemental kinetics laws (d[F]/dt = -k1. [F][S]), we propose to determine two new parameters characteristic of the degradation of the system during the sintering process. Finally, three types of parameters (D, n, k1) are available to describe the chemical evolutions in composites.