Thermoanalytical studies of zinc citrate, bismuth citrate and calcium citrate

Abstract

hermal decomposition behaviour of the citrates of zinc, bismuth and calcium has been investigated individually and as binary mixtures (1:1) consisting of zinc citrate as the essential component. Zinc citrate is found to decompose to zinc oxide at 400° C, bismuth citrate decomposes to α -Bi₂O₃ at 360° C and calcium citrate decomposes to calcium oxide at 1150° C. The barium and calcium oxides which are normally formed at a higher temperature during the individual decomposition of the citrates are obtained at lower temperatures, i.e. 1140 and 800 °C, respectively, on decomposition of their mixtures with zinc citrate. Bismuth citrate alone is found to decompose to α-Bi₂O₃ whereas its mixture with zinc citrate decomposes to the β-phase of bismuth oxide.