The phase diagram of the system CdI2-Bi2O3 is studied by means of X-ray diffraction, differential thermal analysis and measurements of the density of the material.
As a result of the synthetic and peritectic interactions, two incongruently melting intermediate phases i.e. phase A - CdI22Bi2O3 and phase B - CdI24Bi2O3 (stable in the temperature interval 370-850C) are formed. The phase A exists in two polymorphic forms with a temperature
of the phase transition Ta↔b=320-370C. The unit cell parameters at low temperature modification of a-CdI22Bi2O3 were determined. (a=1.032 nm, b=1.046 nm, c=1.046 nm, α=115.02, β=109.11 and γ=82.04). The phases A and B have fields of homogeneity.