Characteristic temperatures of glassy behaviour in a simple liquid.

A model for the metastable liquid in terms of holes present in the amorphous structure is considered using the classical density functional theory (DFT). For a one component Lennard-Jones liquid we obtain the temperature dependence of the free volume v(f) in the metastable state. A temperature T(0), similar to that of the characteristic transition of the free volume theory, is identified by extrapolating v(f)(T) to zero. The Kauzmann temperature T(K) is also obtained here by extrapolating the entropy difference between the supercooled state and that of the crystal to zero. We compare the temperatures T(0) and T(K) obtained in our model with other two characteristic temperatures for glassy behaviour, namely (a) the dynamic transition temperature T(c) of the mode coupling theory (MCT) and (b) the glass transition temperature T(g) which was obtained by Leonardo et al (2000 Phys. Rev. Lett. 84 6054) from studying the violation of the fluctuation-dissipation theorem. All the four temperatures, obtained from independent routes, are located with respect to the melting temperature T(m) in a manner which is in agreement with experiments.