Papers by Thierry Epicier
ECS Meeting Abstracts
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ECS Meeting Abstracts
not Available.
European Microscopy Congress 2016: Proceedings, 2016
Microscopy and Microanalysis, 2016
Physical Review B, 1999
The formation of C54 TiSi2 with a thin Ta layer deposited between Si and Ti is investigated at at... more The formation of C54 TiSi2 with a thin Ta layer deposited between Si and Ti is investigated at atomic scale level using transmission electron microscopy. When the Si/Ta/Ti structure is annealed at 650 °C for 30 s, both C40 and C54 (Ti,Ta)Si2 are found at the Si/silicide interface. The Ta-to-Ti ratio in such C40 or C54 grains changes rapidly from
EMC 2008 14th European Microscopy Congress 1–5 September 2008, Aachen, Germany, 2008
ABSTRACT Nano-tomography in Transmission Electron Microscopy (TEM) has been recently and successf... more ABSTRACT Nano-tomography in Transmission Electron Microscopy (TEM) has been recently and successfully applied to the characterization of various precipitates embedded in a matrix (see for example [1,2]). In this context we have undertaken a study of the precipitation state of MgZn2-based particles in the Al-Mg-Zn system. The material is a medium-strength commercial alloy extensively used for automotive applications, where weldability is an important feature. A previous characterization by means of TEM, Small-Angle X-ray Scattering (SAXS) and Atom Probe Tomography (APT) [3] has shown that, in the so-called T7 tempering state (6 hrs. at 170°C): (i) the stable η-MgZn2 phase (hexagonal P63/mmc structure) mainly precipitates under the form of spheres, while minor variants, called η′, adopt a platelet shape; (ii) the total precipitated volume fraction, as measured by SAXS, is 2.54 ± 0.3 %; (iii) the precipitates mean radius is 3.6 nm with a standard deviation of 1.0 nm. According to the above size and volume fraction, TEM tomography appears as an interesting alternative tool to SAXS, with which it can be delicate to discern the η and η′ particles, and to APT, for which the density of precipitates makes any statistical approach hazardous.
EMC 2008 14th European Microscopy Congress 1–5 September 2008, Aachen, Germany, 2008
Hybrid gold and Silica nano-composites (Au@ SiO x) can be used for photonic, optical and biomedic... more Hybrid gold and Silica nano-composites (Au@ SiO x) can be used for photonic, optical and biomedical applications, for example for the development of novel contrast agents in magnetic resonance imaging (eg [1]). According to the synthesis conditions, these nano-...
MRS Proceedings, 1990
This paper gives an overview of recent High Resolution Electron Microscopy (HREM) observations of... more This paper gives an overview of recent High Resolution Electron Microscopy (HREM) observations of transition metal carbides. The main point is to show how HREM can be used to study a sublattice of light atoms within a complex crystal. General tendencies of this approach will be outlined, which appear, to a large extent, to be common to similar possible studies of other compounds such as nitrides, borides or oxides. Specifically, attention is focused on studies of long-range ordered structures in carbides, due to non-stoichiometry accommodated by metalloid vacancies. Various examples are given for representative compounds, including V8C7, V6C, 5, Nb6C5 and W2C.
J. Mater. Chem. C, 2014
The main goal of this work is to conjugate two independent techniques of TEM-EDX and optical spec... more The main goal of this work is to conjugate two independent techniques of TEM-EDX and optical spectroscopy, which is rare, for the localization of Yb 3+ and Er 3+ rare earth ions and Co 2+ transition metal ions as dopants in a compact self-Q-switched microchip laser glass ceramic composed of MgAl 2 O 4 spinel nano-crystals of 10-20 nm size embedded in SiO 2 glass. The use of the TEM-EDX technique associated with both the elemental mapping of each dopant and the direct visualization of the heavier rare earth ions has led to the result that Er 3+ and Yb 3+ rare earth ions are preferentially located in the spinel nano-crystals. Regarding the low Co 2+ concentration this technique was not accurate enough for characterization and finally we have used absorption spectroscopy to probe the main presence of Co 2+ ions in the spinel nano-crystals. The use of Yb 3+ ions as structural probes allows the identification of the 0-phonon broad line at 977 nm as both that of the disordered glass and that of the spinel inverted phases. A new Yb 3+ radiationless center has been pointed out by the presence of a strong absorption line at 970 nm which has been assigned to the strongly perturbed area of the spinel nano-crystallite surface. This dopant characterization is worthwhile to be shown as a special case where characterization of rare earth and transition metal ions needs the use of both TEM and spectroscopic techniques.
Philosophical Magazine A, 1989
High-resolution electron microscopy (HREM) has been applied to the study of the order-disorder ph... more High-resolution electron microscopy (HREM) has been applied to the study of the order-disorder phenomena in vanadium carbide VC1−x near the composition V6C5. HREM images have been obtained by collecting in the objective aperture superstructure spots associated with the ordered distributon of vacancies in the carbon sublattice. Direct interpretation of experimental micrographs can be done for particular imaging conditions which are
Ceramic Engineering and Science Proceedings, 2007
Journal of Materials Research, 2014
Revue de Métallurgie, 2003
ABSTRACT During the last 5 years, the semi-conductor industry has enhanced device performances by... more ABSTRACT During the last 5 years, the semi-conductor industry has enhanced device performances by scaling down the feature sizes and by introduction of new technologies. Transmission electron microscopy with high resolution images (HREM) has become an indispensable tool for analyzing devices structure at nanoscale, for failures analysis, defects review and manufacture controlling. In parallel to this progress on the devices, the sample preparation techniques for MET compatible with the requirements of the industrial world were developed and open new prospects. In this paper, we present these techniques of sample preparation. Then we show examples in what high resolution images make it possible to answer industrial problems.
Thin Solid Films, 2006
In this paper first we prove common fixed point theorems for compatible and weakly compatible map... more In this paper first we prove common fixed point theorems for compatible and weakly compatible maps. Secondly, we prove common fixed point theorems for weakly compatible maps along with property (E.A.) and (CLRg) property respectively.
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Papers by Thierry Epicier