Influence of iron content on the electrical and dielectric properties of La0.7Ba0.3Co1-yFeyO3

Powders of La(0.7)Ba(0.3)Co(1-y)FeyO(3), LBCF, y = 0.0 to 1.0, were prepared by thermal decomposition of metal polymerized complex solutions. Thermal and chemical analyses of cation concentrations were used to confirm the desired composition sintered at 900 degreesC. Powder X-ray diffraction data indicate that all compositions possess the perovskite structure. Cubic unit cell parameters increase with increasing iron content except for y = 0.3, which was explained in terms of the average valencies and charge neutrality of Fe and Co ions and oxygen ion deficiency. The electrical properties such as conductivity, dielectric constant and dielectric loss factor of the LBCF samples were studied as a function of frequency (100 Hz-1 MHz) and temperature (293-625 K). Iron substituted samples exhibit semiconductor behavior with decreased electrical conductivity values compared to that of the free Fe sample. The possible conduction mechanisms were discussed. Dielectric studies show apparent high dielectric behavior, which was explained by the double layer capacitor model.