EPR Monitoring of BaTiO3 Formation

BaCO3 and anatase-type TiO2 were adopted as initial materials to prepare BaTiO3 powder by the solid-state reaction method at a heating rate of 350°C/h. The electron paramagnetic resonance (EPR) technique was employed to monitor the formation of BaTiO3. TiO2 showed a series of complicated EPR signals associated primarily with Fe impurities. The formation of BaTiO3 can be monitored in terms of the evolution of EPR signals associated with Fe impurities with calcination and measurement temperatures. The activation of the g = 2.004 signal above the Curie point of BaTiO3 and the disappearance of the other EPR signals in the BaCO3/TiO2 mixture at room temperature are characteristic of the formation of BaTiO3.