Thermal decomposition process and electrical conductivity of single crystals of NH+4-β- and β″-ferrites
Abstract The thermal decomposition process and the ionic and electronic conductivities of NH + 4 -β-ferrite and Cd stabilized NH + 4 -β″ ferrites single crystals were investigated. TG curves of both ferrites exhibited the two steps of weight loss at 50–200°C and 300–430°C. The first weight loss was based on dehydration, while the second was due to the liberation of NH + 4 ions. The β and β″ structure decomposed with the loss of NH + 4 ions to form α-Fe 2 O 3 and Cd doped γ-Fe 2 O 3 , respectively. The ionic conductivities of NH + 4 -β- and β″-ferrite single crystals were 4×10 −6 S cm −1 and 3×10 −5 S cm −1 at 25 °C, respectively. Temperature dependence of ionic and electronic conductivities is discussed in terms of the thermal decomposition process.