CRITICAL VERSUS TRICRITICAL PHASE-TRANSITIONS IN SYMMETRICAL ELECTROLYTES

In view of recent experimental results on phase transitions in symmetric electrolytes, we have critically reanalyzed our previous theoretical treatment of this problem [Phys. Lett. A 132 (1988) 347]. In this Letter we discuss the possibility of tricritical behavior in symmetric electrolytes. It is argued that the phase behavior of symmetric electrolytes could be well understood by employing the antiferromagnetic version of the Blume-Emery-Griffiths model. We provide a Landau-type analysis of this model which yields the exponents gamma = 1 and beta = 1/2 observed in recent experiments.