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arXiv 0808.4036cond-mat.softcond-mat.stat-mech
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具有竞争相互作用的胶体流体相行为理论

Theory for the phase behaviour of a colloidal fluid with competing interactions

A. J. Archer, C. Ionescu, D. Pini, L. Reatto

摘要:

我们研究的相行为的粒子通过一对潜在的相互作用,是排斥大粒子间的距离,是有吸引力的中间距离,并强烈排斥在短距离(粒子有一个硬核)的流体组成。除了表现出气-液相分离之外,该系统还表现出从均匀流体相到调制的不均匀流体相的相变。从微观密度泛函理论出发,我们发展了一个相变的序参量理论,以便详细地研究相行为。在我们的理论中,密度调制的振幅是序参量。该理论预测,从均匀流体相到调制流体相的相变可以是一阶或二阶(连续的)。该相图显示了两个三临界点,通过二级跃迁线彼此连接。

英文摘要:

We study the phase behaviour of a fluid composed of particles which interact via a pair potential that is repulsive for large inter-particle distances, is attractive at intermediate distances and is strongly repulsive at short distances (the particles have a hard core). As well as exhibiting gas-liquid phase separation, this system also exhibits phase transitions from the uniform fluid phases to modulated inhomogeneous fluid phases. Starting from a microscopic density functional theory, we develop an order parameter theory for the phase transition in order to examine in detail the phase behaviour. The amplitude of the density modulations is the order parameter in our theory. The theory predicts that the phase transition from the uniform to the modulated fluid phase can be either first order or second order (continuous). The phase diagram exhibits two tricritical points, joined to one another by the line of second order transitions.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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