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Marie-Claire Bellissent-Funel

Publications and source records attributed to Marie-Claire Bellissent-Funel.

2 recordsLinked to original sources

Structural evidence for the continuity of liquid and glassy water

An open question is whether the liquid and glassy phases of water are thermodynamically distinct or continuous. Here we address this question using molecular dynamics simulations in comparison with neutron scattering experiments to study the effect of temperature and pressure on the local structure of liquid water. From both simulations and experiments, we find that the liquid structure at high pressure is nearly independent of temperature, and remarkably similar to the known structure of the high-density amorphous ice (HDA). Further at low pressure, the liquid structure appears to approach the experimentally-measured structure of low-density amorphous ice (LDA) as temperature decreases. These results are consistent with continuity between the liquid and glassy phases of H$_2$O.

cond-mat↗

Experimental Indication of Structural Heterogeneities in Fragile Hydrogen-bonded Liquids

We present the first experimental characterization in molecular fragile glassformers of a 'prepeak that appears significantly below the main peak of the static structure factor. The temperature and density dependences of this prepeak are studied via elastic neutron scattering experiments under high pressure (up to 300 MPa) in m-toluidine and m-fluoroaniline. The prepeak intensity increases with decreasing temperature, but it remains constant with increasing pressure while its position and width stay roughly the same. These features are opposite to those observed for the 'first sharp diffraction peak' of network glasses. The origin of the phenomenon is analyzed with the help of Monte Carlo simulations. We associate the prepeak to hydrogen-bond-induced heterogeneities (or clusters) whose limited size results from exclusion effect between benzene rings that prevents the extension of a hydrogen-bond network. Implications for the dynamics of the liquid close to the glass transition are finally considered.

physics.chem-ph↗