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Density anomaly in a competing interactions lattice gas model

Alan B. de Oliveira·Marcia C. Barbosa
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Abstract

We study a very simple model of a short-range attraction and an outer shell repulsion as a test system for demixing phase transition and density anomaly. The phase-diagram is obtained by applying mean field analysis and Monte Carlo simulations to a two dimensional lattice gas with nearest-neighbors attraction and next-nearest-neighbors repulsion (the outer shell). Two liquid phases and density anomaly are found. The coexistence line between these two liquid phases meets a critical line between the fluid and the low density liquid at a tricritical point. The line of maximum density emerges in the vicinity of the tricritical point, close to the demixing transition.

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Alan B. de Oliveira, Marcia C. Barbosa. 2004-09-06. Density anomaly in a competing interactions lattice gas model. https://doi.org/10.1088/0953-8984%2F17%2F3%2F001

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