Maxwell-Wagner relaxation in grain boundary of BaBixLaxYxFe12-3xO19 (0.0 <= x <= 0.33) hexaferrites

Abstract

In this study, it was aimed to synthesize and to investigate the AC conductivity mechanism and dielectric properties of BaBixLaxYxFe12-3xO19 (0.0 <= x <= 0.33) hexaferrites. The AC conductivity analyzed in the frequency range of 1 Hz to 1 MHz and temperature (20-120 degrees C) using complex impedance spectroscopy technique. The relaxation behaviours were examined by considering modulus formalism. Two different relaxation times dependent on two different relaxation processes where grain and grain boundary takes role was determined in the chosen frequency and temperature range. Therefore three frequency regions were determined which are low frequency region (LFR) (1-50 Hz), middle frequency region (MFR) (50 Hz - 50 KHz) and high frequency region (HFR) (50 KHz - 1 MHz) belonging to these relaxation processes. The activation energies of all products are similar and the relaxation process may be attributed to the same type of charge carriers. The study related with the electrical and dielectric properties of ferrite materials, as a function of temperature, is important for microwave absorption applications. The protection of sensitive circuits from the interference of external microwave radiations is an important technological application of these materials. (C) 2016 Elsevier Ltd. All rights reserved.