Critical temperatures of two phase transitions in mixtures of spherical and ellipsoidal molecules

In this paper we have derived, in the usual molecular field approximation, an equation for the thermodynamic potential for determining the critical temperatures of two phase transitions in a mixture of ellipsoidal and spherical molecules. These molecules are dispersed on b.c.c.-lattice and their ratio of concentrations is different form 1:1. We have also obtained the bound lines of the orientational and positional transitions in the temperature-concentration diagram for different values of molecular parameter (of ellipsoidal molecules) and interaction parameters. (author). 15 refs, 2 figs, 1 tab