1206.1572 (Marco Aurélio A. Barbosa et al.)

Multiple liquid-liquid critical points and anomalies in core-softened
potentials    [PDF]

Marco Aurélio A. Barbosa, Evy Salcedo, Marcia Barbosa

Using an exact soluble 1D model and numerical simulations of an equivalent 3D potential we show that a three length scales potential exhibits three critical points and two density anomalous regions if the different length scales would be accessible. In addition we propose propose a new way to identify if a liquid-liquid critical point would be present by exploring the behavior of the thermal compressibility for temperatures above the critical temperature. We show that for systems in which there is a density anomalous region close to criticality, the thermal expansion coefficient exhibits a peculiar behavior diverging to $\infty$ for pressures above the critical pressure and to $-\infty$ for pressures below the critical pressure. To the best of knowledge this is the first time that a spherically symmetric potential is shown to have three critical points and two temperature of maximum density lines.

View original: http://arxiv.org/abs/1206.1572