CNRS Laboratory of Physical Chemistry of Luminescent Materials

Lyon, France

CNRS Laboratory of Physical Chemistry of Luminescent Materials

Lyon, France
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Guyot Y.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Boulon G.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Journal of Rare Earths | Year: 2013

Phosphate glass samples with various Yb2O3 and Er2O3 contents were synthesized by the conventional melt quenching technique and characterized by X-ray diffraction, IR absorption spectroscopy and Raman scattering spectroscopy. The absorption, emission spectra and fluorescence decay studies were carried out both at low and room temperatures. Results showed the existence of several sites occupied by the rare earth ions in the phosphate glass. Up-conversion and cooperative fluorescence were also discussed. © 2013 The Chinese Society of Rare Earths.


Jierry L.,Charles Sadron Institute | Harthong S.,Ecole Normale Superieure de Lyon | Aronica C.,Ecole Normale Superieure de Lyon | Mulatier J.-C.,Ecole Normale Superieure de Lyon | And 2 more authors.
Organic Letters | Year: 2012

Herein, we describe our recent expeditious synthesis of dibenzo[c]acridine helicene-like compounds on a large scale in pure enantiomeric form. This flexible synthesis allows for variation at several positions on the skeleton. Geometrical parameters related to these compounds have been obtained from monocrystal X-ray structure resolution. Additionally, chiroptical parameters have been recorded, highlighting the versatility of this family showing for example optical rotation at 589 nm varying between 135 and 150 deg g -1cm 2. © 2011 American Chemical Society.


Sathe B.R.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Balan B.K.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Pillai V.K.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Applied Physics Letters | Year: 2010

Manipulating the surface to tune plasmonic emission is an exciting fundamental challenge and here we report on the development of unique morphology-dependant optical features of Rh nanostructures prepared by an equilibrium procedure. The emergence of surface plasmon peaks at 375 nm and 474 nm, respectively, is ascribed to truncated and smooth surface of nanospheres in contrast to the absence of surface plasmon for bulk Rh(0) in the visible range. Smaller sized, high surface area domains with well developed, faceted organization are responsible for the promising characteristics of these Rh nanospheres which might be especially useful for potential catalytic, field emission and magnetic applications. © 2010 American Institute of Physics.


Guille A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Pereira A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Martinet C.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Moine B.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Optics Letters | Year: 2012

The deposition of a thin layer of a quantum-cutter material on top of silicon-based solar cells seems to be a promising solution to reduce the thermalization losses. This mechanism has been reported in materials codoped with Pr3+ - Yb3+, where Pr3+ can sensitize two Yb3+ ions for one absorbed blue photon. In the present Letter, we analyze precisely energy transfers between Pr3+ and Yb3+ in CaYAlO4, and we measure a quantum-cutting rate of 145%. We show that a very efficient back transfer from Yb3+ toward the 1G 4 level of Pr3+ ion leads to a strong reduction of the quantum yield. © 2012 Optical Society of America.


Brenier A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Laser Physics Letters | Year: 2011

We have demonstrated a simple and compact tunable dual-wavelength Yb 3+:KGd(WO 4) 2 (Yb:KGW) laser. The laser is diode pumped through an optical bifurcated fiber and an adjustable beamsplitter. Thanks to two transversally chirped volume Bragg gratings (TCVBG) used as output couplers, the frequency difference between the two collinear waves is continuously tunable from 0 up to 7.8 THz with 110 GHz bandwidth. The frequency range is only limited by non optimized optical components and not by the principle of functioning. © 2011 by Astro Ltd., published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA.


Brenier A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Alombert-Goget G.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Guyot Y.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Boulon G.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Laser Physics Letters | Year: 2012

The absorption and fluorescence properties of the Nd-doped YGd2Sc2Al2GaO12 mixed garnet ceramics have been measured at different temperatures. Under laser diode pumping an efficient laser emission has been demonstrated with 45% slope efficiency. The emission is constituted by two lines at 1058.6 and 1061.3 nm, subjected to a red shift and a variable relative intensity versus pump power. The role of the temperature has been investigated playing with the cavity parameters. The thermal conductivity of the 1% Nd-doped material has been determined (3.2 W/m/K) measuring the radial temperature distribution of the exit face of the sample including the axial heat flow in the analysis. The M2 beam quality factor and the dioptric power of the thermal lens have been investigated versus the pump power. The thermo-optic coefficient X was determined as 44.4×10-6 K-1. © 2012 by Astro, Ltd.


Shoval S.,Open University of Israel | Yadin E.,Tel Aviv University | Panczer G.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Journal of Thermal Analysis and Calorimetry | Year: 2011

The work deals with the FT-IR and micro- Raman spectroscopy study of the pseudo-amorphous and crystalline thermal phases in the composition of calcareous Iron Age pottery from the Galilee. The application of second-derivative and curve-fitting techniques improves the identification of the thermal phases in the composition of the pottery and makes it possible to analyze the pseudoamorphous phases which are formed during the firing of the clayey raw material to pottery. This technique makes it possible to distinguish between meta-smectite and metakaolinite and to estimate the firing temperature of the pottery. The Micro-Raman spectroscopy is sensitive to the structural degree of ordering of the thermal phases and enables point analysis of peculiar components in the composition of the pottery. Based on the spectroscopic study, it is concluded that the calcareous pottery contained large amounts of microcrystalline-recarbonated calcite mixed with the meta-clay. The large amount of recarbonated calcite in the pottery material and the relatively low firing temperature indicates that instead of sintering the clay, lime technology was used for the cementation of the calcareous vessels. This process took place after the firing by recarbonation of the decomposed calcite which leads to cementation of the vessels with microcrystalline calcite. © 2011 Akadémiai Kiadó, Budapest, Hungary.


Shoval S.,Open University of Israel | Boudeulle M.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Panczer G.,CNRS Laboratory of Physical Chemistry of Luminescent Materials
Optical Materials | Year: 2011

Firing of kaolinite to mullite is an important process in ceramic industry. In the present study, Raman spectroscopy and curve-fitting are utilized for identification of the thermal phases in progressive firing of kaolinite to mullite up to 1300 °C. The results are compared to that observed by XRD. Many natural kaolinites consist of accessory anatase, and this mineral has strong Raman bands. Therefore, the spectra of anatase-free and anatase-containing kaolinites were analyzed. The Raman response is sensitive to the degree of the structural order of the thermal phases. Dehydroxylated kaolinite is detected at 500 °C by the disappearance of the Raman bands of the kaolinite. The metakaolinite at 700 °C and the spinel-type phase at 1000 °C have broad and weak Raman bands due to their short-range and poorly-order structure, respectively. Amorphous silica is observed at 1000 °C by the development of diagnostic broad and weak Raman bands. Mullite and cristobalite are detected at 1300 °C by the appearance of characteristic Raman bands. In firing of anatase-containing kaolinite, progressive thermal transform from anatase to rutile is observed at 1100-1300 °C by the appearance of Raman bands of rutile and by the decreasing of the anatase bands. The results can be applied in using micro-Raman spectroscopy as a non-destructive method for identification of thermal phases in the composition of modern and ancient ceramic. © 2011 Elsevier B.V. All rights reserved.


Brenier A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Wu Y.,CAS Institute of Chemistry | Zhang J.,CAS Institute of Chemistry | Wu Y.,University of Chinese Academy of Sciences
Applied Physics B: Lasers and Optics | Year: 2012

We report spectroscopic and laser properties for propagation directions outside the principal axes of Yb 3+-doped low symmetry laser crystals with a special devotion to the wavelength dependence anisotropy. We illustrate our report with experimental data in the 900-1075 nm range of wavelengths from the Yb 3+:La 2CaB 10O 19 monoclinic crystal excited under laser diode pumping at 975 nm. This study, which makes easier the realization of Yb 3+ lasers with an efficient free-running operation at the wavelength having the highest emission intensity or at a specified wavelength, or emitting two frequencies with a specified frequency difference, is of promising interest for applications. © 2011 Springer-Verlag.


Garbarino S.,INRS E nergie | Pereira A.,CNRS Laboratory of Physical Chemistry of Luminescent Materials | Hamel C.,INRS E nergie | Irissou E.,INRS E nergie | And 2 more authors.
Journal of Physical Chemistry C | Year: 2010

Pulsed laser deposition was used to prepare Pt nanoparticles of various sizes ranging from 1.8 to 6.0 nm.These nanoparticles were deposited on highly oriented pyrolytic graphite (HOPG) and gold substrates. For Pt deposited on HOPG and Au, the size of the nanoparticles was established by scanning tunneling microscopy (STM) and calculated from the electrochemically active surface area (EASA) obtained through measurements of the hydrogen underpotential deposited charges, QHupd. The diameters determined from these two sets of measurements agreed with each other to within 60%. X-ray photoelectron spectroscopy (XPS) was used to assess the size of the nanoparticles before and after an electrochemical treatment that involved potential cycling in 0.5 M H2SO4. The upper potential limit was progressively increased from 1.15 to 1.40 V in steps of 0.05 V, and the EASA was continuously monitored. The EASA decreased with cycle number and with increasing upper potential limit to 1.35 V vs RHE. This effect was found to be larger for the smaller Pt nanoparticles (50% decrease for φ ) 1.8 nm) than for the larger ones (20% decrease for φ ) 3.0 nm). It was found by XPS that the diameter of the smaller Pt nanoparticles increased from φ ) 1.8 nm to φ ) 6.5 nm as a result of the electrochemical treatment, whereas the diameter of the larger nanoparticles (φ ) 3.0 nm) remained constant. In this potential range, the corrosion of the gold substrate is minimal, and this observation can be explained by an increase of the equilibrium soluble Pt concentration with decreasing Pt nanoparticle diameter. © 2010 American Chemical Society.

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