A STUDY ON THE THERMAL-DECOMPOSITION OF IRON-COBALT MIXED HYDROXIDES

Thermal decomposition of pure Fe(OH)3 and mixed with Co(OH)2 were stud ied using TG, DTA, kinetics of isothermal decomposition and electrical conductivity measurements. The thermal products were characterized by X-my diffraction and IR spectroscopy. The TG and DTA analysis reveale d the presence of Co2+ retards the decomposition of ferric hydroxide a nd the formation of alpha-Fe2O3. The kinetics of decomposition showed that the mixed samples need higher energy to achieve thermolysis. The investigation of thermal products of mixed samples indicated the forma tion of cobalt ferrite on addition of x = 1 or 1.5 cobalt hydroxide. T he electrical conductivity accompanying the thermal decomposition decr eases in presence of low ratio of Co2+(x = 0.2) via the consumption of holes created during thermal analysis. The continuous increase in sig ma values on increasing of Co2+ concentration corresponded to the elec tron hopping between Fe2+ and Co3+.