Effects of the attractive interactions in the thermodynamic, dynamic, and structural anomalies of a two length scale potential

• Autor(a) principal: Silva, Jonathas Nunes da
• Data de Publicação: 2010
• Outros Autores: Torres, Evy Augusto Salcedo, Oliveira, Alan Barros de, Barbosa, Marcia Cristina Bernardes
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/205081
• topic: Diagramas de fase; Difusão; Dinâmica molecular; Propriedades termodinâmicas

Using molecular dynamic simulations, we study a system of particles interacting through a continuous core-softened potentials consisting of a hard core, a shoulder at closest distances, and an attractive well at further distance. We obtain the pressure–temperature phase diagram of this system for various depths of the tunable attractive well. Since this is a two length scale potential, density, diffusion, and structural anomalies are expected. We show that the effect of increasing the attractive interaction between the molecules is to shrink the region in pressure in which the density and the diffusion anomalies are present. If the attractive forces are too strong, particle will be predominantly in one of the two length scales and no density of diffusion anomaly is observed. The structural anomalous region is present for all the cases.