Effect of annealing time, weight pressure and Fe doping on the electrical and magnetic behavior of calcium titanate

CaFexTi1-xO3; 0.05 <= x <= 0.6 perovskites were synthesized by the standard ceramic technique at different annealing times. XRD analysis clarified the presence of two types of crystal structure, orthorhombic for x = 0.05 and 0.2 and monoclinic for x = 0.4 and 0.6. The annealing time increases the crystal size without any change in the crystal structure. The first order phase transition is the common character. These compounds behave like semiconductor materials characterized by more than one conduction mechanism as it was found from the results of activation energy. This type of perovskite has a piezoelectric like behavior The. variation of resistivity with time due to load increases with increasing Fe content as well as with increasing the annealing time. Also, the ferromagnetic character increases with increasing Fe content and decreases with increasing annealing time. The obtained results indicate that these compounds can be use in wide range of applications. (C) 2008 Elsevier B.V. All rights reserved.