New double complex bismuth salts of the general formula Cs2K[Bi(SCN)(x
)I-6-x] where x = 1, 2 and Cs2K[Bi-2(SCN)(y)I-9-y] where y = 5, 6, 7 h
ave been obtained by dissolving Cs[Bi(SCN)(4)] in KI solutions of vari
ous concentrations. The mechanism of the thermal decomposition of thes
e compounds has been determined on the basis of thermal curves, chemic
al and diffractometric analyses of the solid pyrolysis products. The d
ecomposition was found to proceed in three stages.