A Study of the Phase Diagram of Symmetric Binary Gaussian Mixtures

  • Davide Pini
Conference paper


We perform an analytic study of the main features of the phase diagram of symmetric binary Gaussian mixtures such that the range and strength of the interactions between particles of one species are the same as those of the other species. We focus on the relative locations of the spinodal and \(\lambda \)-lines, i.e., the boundaries beyond which the uniform mixture becomes unstable respectively towards bulk demixing and microphase formation. We find that, when the \(\lambda \)-line is present, three situations may occur: (i) The spinodal line does not exist, and the \(\lambda \)-line spans the whole concentration axis. (ii) Both the \(\lambda \)- and spinodal lines are present and span the whole concentration axis, but the spinodal instability is always preempted by the \(\lambda \)-line. (iii) The spinodal instability is the only one present at intermediate concentrations, but is preempted by the \(\lambda \)-line at high and low concentrations.


Gaussian mixture Spinodal line \(\lambda \)-line Random-phase approximation 


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© Springer Nature Switzerland AG 2018

Authors and Affiliations

  1. 1.Dipartimento di Fisica “Aldo Pontremoli”Università degli Studi di MilanoMilanItaly

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