Bruno Mercier - Academia.edu (original) (raw)

Papers by Bruno Mercier

This paper presents an electrical model of bonding wire effects. This model fits in Ka to W bands... more This paper presents an electrical model of bonding wire effects. This model fits in Ka to W bands and it can be easily used in an electrical simulator. It takes into account the different coupling effects which appear in such structures and it uses analytical formulas to calculate the components of the equivalent circuit. This bonding wire electrical model has been validated by comparing it to 3D electromagnetic simulations and measures. Bonding wire structures have been realised with a MEMs technique developed on a Silicon substrate and they have been characterised up to 110 GHz. The model and the results of simulations and measures are presented and prove that the bonding wire technique can be used in the millimeter wave band.

IEEE Journal of Quantum Electronics, 2001

ABSTRACT We show that the lineshape and size of the detected signal in ultra-high-resolution stim... more ABSTRACT We show that the lineshape and size of the detected signal in ultra-high-resolution stimulated Raman spectroscopy computed from a general expression of the modulated signal are in good agreement with the experimental results. Using the theoretical expression of the signal, we analyze the resolving power and the sensitivity of our Raman spectrometer. We show that a second harmonic detection in high-frequency transfer modulation generates a lineshape without modulation broadening. A 2.6-kHz-wide resonance has been obtained with iodine, mainly limited by both the transit time and collisions

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European Physical Journal D, 1999

Excited states of the Z = 102 nuclide 254No have been studied in the reaction 208Pb(48Ca,2n) by m... more Excited states of the Z = 102 nuclide 254No have been studied in the reaction 208Pb(48Ca,2n) by means of in-beam γ -ray spectroscopy in combination with recoil gating and recoil decay tagging. A Ge detector array, consisting of four clover detectors, and a gas-filled separator were used. Six γ-ray lines were observed and associated with E2 transitions in the ground state band of 254No, the highest-lying of these being the 16+→ 14+ transition. Based on global systematics and the extrapolated 2+1 excitation energy, the value β2= 0.27 ± 0.03 was extracted for the quadrupole deformation. An improved value for the half-life of 254No, T1/2= (48 ± 3) s, was determined.

Physical Review D, 2001

We consider the classical equations of the Born-Infeld-Abelian-Higgs model (with and without coup... more We consider the classical equations of the Born-Infeld-Abelian-Higgs model (with and without coupling to gravity) in an axially symmetric ansatz. A numerical analysis of the equations reveals that the (gravitating) Nielsen-Olesen vortices are smoothly deformed by the Born-Infeld interaction, characterized by a coupling constant beta2\beta^2beta2, and that these solutions cease to exist at a critical value of beta2\beta^2beta2. When the critical value is approached, the length of the magnetic field on the symmetry axis becomes infinite.

Radiation Measurements, 2004

This paper reports on the synthesis and characterization of Gd2O3:Eu 3+ nanocrystals of di erent ... more This paper reports on the synthesis and characterization of Gd2O3:Eu 3+ nanocrystals of di erent sizes. The particles have been synthesized by a sol-lyophilization process. This methods allows the synthesis of 7-100 nm diameter cubic-phase particles. The photoluminescence properties have been studied with di erent excitation from X-ray to VUV and visible wavelengths. Compared to the properties of the bulk materials, some important changes on the luminescence are observed. In particular some bands are strengthened when the size of the particles is diminished. We could therefore ascribe this bands to doping ions on a site close to the surface. Also a very low e ciency of excitation for small particles is observed when exciting with X-ray or high-energy VUV photons (i.e. when exciting the host matrix) compared to the e ciency obtained when exciting in the charge transfer band or in the doping ions related states.

European Physical Journal D, 2005

We investigate the fundamental properties of films resulting from the deposition of Eu3+ doped Gd... more We investigate the fundamental properties of films resulting from the deposition of Eu3+ doped Gd2O3 clusters. We first report that the crystalline structure of clusters with diameter as low as 2.8 nm is still BCC (as in the bulk phase at ambient temperature and pressure). No phase transition to monoclinic structure is observed. We show that contamination from air (formation of hydroxide) is important and leads to the modification of the luminescence of the Eu3+ ions. Furthermore, films protected from this contamination have been fabricated and show a new feature (broad peak at 625 nm). It means that contamination is not the only mechanism responsible for the modification of the light emission spectrum. The crystal field symmetry breaking induced by the surface also plays a major role. Eventually, we show that the widening of the optical gap continues for these very small clusters. We discuss this effect in the frame of the quantum confinement model.

Journal of Luminescence, 2006

When the size of a particle is decreased to nano-scales, confinement effects induce strong change... more When the size of a particle is decreased to nano-scales, confinement effects induce strong changes. The luminescence of Eu 3+ -doped Gd 2 O 3 nanoparticles has been studied as a function of both the temperature and the size of the nanoparticles.

Journal of Colloid and Interface Science, 2004

Nanocrystals of oxides containing europium as the main constituent or as a doping element in RE 2... more Nanocrystals of oxides containing europium as the main constituent or as a doping element in RE 2 O 3 (RE = Y, Gd) have been prepared by direct oxide precipitation in high-boiling polyalcohol solutions and characterized by high-resolution TEM, absorption spectroscopy, and luminescence spectroscopy. The samples obtained consisted of concentrated and colloidally stable suspensions of luminescent oxide nanoparticles with an average grain diameter in the range 2-5 nm. The nanoparticles were found to be highly crystalline despite their ultrasmall size and the low temperature of 180 • C applied during the synthesis. Upon UV excitation, the red luminescence relative to the 5 D 0 → 7 F n transition within the cubic form of RE 2 O 3 exhibits some important differences from that usually found in bulk materials.

Journal of Luminescence, 2007

Spectroscopic behaviour of Y 2 O 3 :Ce 3+ nanocrystals are presented. A new fluorescence peaking ... more Spectroscopic behaviour of Y 2 O 3 :Ce 3+ nanocrystals are presented. A new fluorescence peaking around 430nm appears in small particles. This emission is interpreted as the 5d-4f radiative recombination of Ce 3+ which does not occur in bulk materials due to autoionisation processes. This change in behavior could be due to both quantum confinement inside the nanoparticles and changes in the crystal field for small sizes corresponding author:Christophe Dujardin, LPCML, 10 rue Ampère 69622 Villeurbannes Cedex. Tel (33) 4 72 43 12 08, Fax (33) 4 72 43 11 30,

Chemistry of Materials, 2005

... synthesis and luminescence properties of a multifunctional Gd 2 O 3 nanoparticles doped by Tb... more ... synthesis and luminescence properties of a multifunctional Gd 2 O 3 nanoparticles doped by Tb 3 ... Their ability to be used as fluorescent nanoprobes for biodetection was investigated. ... chosen because it constitutes an excellent host matrix for the luminescent rare-earth ions such ...