MIXED HALIDES A(3)(I)B(2)(V)C(9)(VII) (A(I)=RB, CS, B-V=SB, BI, C-VII=BR, I) AND THEIR SOLID-SOLUTIONS

Earlier phase-diagram data are used to calculate the dissociation para meters of molten halides A(3)(I)B(2)(V)C(9)(VII) (A(1) = Rb, Cs; B-V = Sb,Bi; C-VII = Br,I) and to identify the most probable dissociation m echanism. The physicochemical properties (melting point, microhardness , band gap, thermal stability in air, enthalpy of melting, and degree of dissociation on melting) of Rb-Cs, Sb-Bi, and Br-I analogs are foun d to correlate to the electronegativies of constituent atoms and bondi ng features, Phase-relationship studies demonstrate that a continuous series of substitutional solid solutions forms in each of the systems Cs3Sb2Br9-Cs3Sb2I9, CS3Sb2Br9Cs3Bi2Br9 CS3Sb2I9-CS3Bi2I9, and Rb3Sb2Br 9-CS3Sb2Br9.