Finite size effects in a supercooled medium under nanoscale solicitations

National audienc

Finite Size Effects and Cooperativity in a Model Diatomic Supercooled Liquid

We use large scale molecular dynamics simulations to investigate the relation between cooperativity and size e ects in a simple diatomic supercooled liquid. We nd that below a characteristic temperature the transport properties depend on the size of the simulation box. is e ect then increases upon decreasing the temperature. For the model molecules constituting our liquid, the smaller box corresponds to the larger di usion coe cient. us, the size e ects increase the di usion of the liquid with our molecules in opposition with previous results concerning silica and atomic so molecules. As a result, the temperature dependence of the di usion coe cient tends to an Arrhenius law for smaller boxes in our simulations. is result is in agreement with a cooperativity origin of non-Arrhenius behavior and size e ects in fragile supercooled liquids, as a small box cuto cooperative motions thus inducing a constant activation energy. To investigate that picture further we then study the size dependence of cooperative motions in our model liquid.

Nonlinear optical studies of Oligomers dyades of polyphenylene using Open aperture z-scan technique

National audienc

Nonlinear optical studies of Oligomers Anisole dyades by Open-aperture z-scan technique

International audienc

Propriétés optiques non linéaires des composés Imino-pyridine-TTF

International audienc

Optical limiting efficiency of an electroactive bis-iminopyridine ligand and its zinc complex

An electroactive based bis-iminopyridine ligand has been synthesized by a condensation reaction between (4-(6,7-dimethyldithio-tetrathiafulvalene)-aniline) with 2,6-diformylpyridine. The complexation of this ligand with ZnCl2 afforded a tetrahedral neutral Zinc metal complex. Nonlinear optical measurements of these structures have given good results in picosecond regime. The nonlinear absorption of the ligand was significantly enhanced upon complexation with ZnCl2. This prompted us to conduct the experiment of optical limiting at wavelength 532nm. The nonlinear absorption properties of these structures were studied and compared to the reference material C60

Optical limiting efficiency of an electroactive bis-iminopyridine ligand and its zinc complex

An electroactive based bis-iminopyridine ligand has been synthesized by a condensation reaction between (4-(6,7-dimethyldithio-tetrathiafulvalene)-aniline) with 2,6-diformylpyridine. The complexation of this ligand with ZnCl2 afforded a tetrahedral neutral Zinc metal complex. Nonlinear optical measurements of these structures have given good results in picosecond regime. The nonlinear absorption of the ligand was significantly enhanced upon complexation with ZnCl2. This prompted us to conduct the experiment of optical limiting at wavelength 532nm. The nonlinear absorption properties of these structures were studied and compared to the reference material C60