Hexatic phase and water-like anomalies in a two-dimensional fluid of particles with a weakly softened core
arXiv:1209.2608 · doi:10.1063/1.4749260
Abstract
We study a two-dimensional fluid of particles interacting through a spherically-symmetric and marginally soft two-body repulsion. This model can exist in three different crystal phases, one of them with square symmetry and the other two triangular. We show that, while the triangular solids first melt into a hexatic fluid, the square solid is directly transformed on heating into an isotropic fluid through a first-order transition, with no intermediate tetratic phase. In the low-pressure triangular and square crystals melting is reentrant provided the temperature is not too low, but without the necessity of two competing nearest-neighbor distances over a range of pressures. A whole spectrum of water-like fluid anomalies completes the picture for this model potential.
26 pages, 14 figures; printed article available at http://link.aip.org/link/?jcp/137/104503
References in corpus (10)
- Phase diagram of Hertzian spheres
- Quasi-binary amorphous phase in a 3D system of particles with repulsive-shoulder interactions
- Metastable liquid-liquid coexistence and density anomalies in a core-softened fluid
- Computer simulations of two-dimensional melting with dipole-dipole interactions
- Phase behaviour of attractive and repulsive ramp fluids: integral equation and computer simulation studies
- Zero temperature phase diagram of the square-shoulder system
- Anomalous phase behavior of a soft-repulsive potential with a strictly monotonic force
- The zero-temperature phase diagram of soft-repulsive particle fluids
- Anomalous melting behavior under extreme conditions: hard matter turning "soft"
- On the accuracy of the melting curves drawn from modelling a solid as an elastic medium