Improvement of Dielectric Properties in Iron-Containing Ferroelectrics

Abstract

Iron-containing ferroelectrics tend to exhibit large dielectric loss accompanied by strong frequency dispersion of the dielectric properties, which is considered to correlate with the partial reduction of Fe3+ to Fe2+ ions during sintering. After sintering in an O2 atmosphere, MnO2 and Li2CO3 dopings exhibit superior behavior in decreasing the dielectric loss of the iron-containing dielectrics. The strong frequency dispersion of the dielectric response and the abnormally recurrent increase of the dielectric constant and loss in the paraelectric region are correspondingly suppressed. An electron compensation mechanism is advanced to interpret the reason for the improvement in dielectric properties in the iron-containing dielectrics, in which the generation of donor electrons is based on different ionization paths.