ABSTRACT
The effect of A1[2]O[3] on the thermal decomposition of cobalt nitrate and its interaction with the produced cobal oxides were investigated using DTA, TG, DTG, X-ray diffraction and IR absorption spectometry techniques. The results obtained evealed that, A1[2]O[3] enhanced the thermal decomposition of cobalt nitrate and decreased its decomposition temperature from 230 to 200C. The produced CoO reacted simultaneously with the evolved NO[2] gas and atmospheric O[2] giving Co[3]O[4] whichremained thermally stable up to about 900C due to dissolution of some of AL[2]O[3] in its lattice resulting in an increase of its oxidation state. Co[3]O[4] interacted with AL[2]O[3] at about 1000C yielding wellcrystalline CoAL[2]O[4] spinel. The AL[2]O[3] employed was poorly crystalline gamma-alumina, being treated with small amount of Co[3]O[4] [.05 mole] and heated in air at 1000C it crystallized to well-crystalline alpha-corrundum which was found to be mostly converted to well-crystalline delta -AL[2]O[3] when subjected to slow cooling [25C/min] to room temperature