The phase diagram of the binary system of bismuth and antimony sesquioxides
were investigated in the air atmosphere in the mole fractions of Bi2O3 bet
ween 0.000 and 0.500. Three different phase regions that were dependent on
the furnace temperature and heating period were obtained by the solid state
reactions. In the first region, a heterogeneous mixture that contained ort
horhombic Sb2O4 and monoclinic BiSbO4 phases occurred in the temperature ra
nge between 700 and 1100 degrees C. In the second region, the heterogeneous
mixture transformed to a homogeneous solid solution that was characterised
by a monoclinic crystal structure (BiSbO4 type). Fusion of the homogeneous
solid solution which decomposed with volatilisation of Sb2O3 took place in
the third region.