Thermodynamic and structural properties of fragile glass-forming toluene and meta-xylene: Experiments and Monte-Carlo simulations

We report a characterization of isobaric and isothermal glass transition of two fragile liquids, toluene and meta-xylene, by elastic neutron scattering calorimetry, and Monte-Carlo simulations. We studied thermodynamic and structural properties in the supercooled and overcompressed liquid up to the glass transition. The simulated thermodynamic or structural properties are in good agreement with experimental ones. From the Prigogine-Defay ratio, the simulated glass transition seems associated to one order parameter. The structural changes in the metastable regime are attributed to density variations. No structural heterogeneity appears on the experimental or simulated neutron spectra.