| Abstract [eng] |
The main task of this work was to measure and investigate dielectric properties of antimony doped barium titanate and nickel ferrite composites (BTS–NF) and nickel–zinc ferrite and barium titanate composites (NZF–BT). The observed dielectric permittivity temperature dependence maximums are rather suppressed and broadened due to high conductivity values, dopants in barium titanate and ferromagnetic phases. Dielectric properties of investigated composites are rather negligible in comparison with pure barium titanate and not suitable for technological applications. Considering the obtained DC conductivity and relaxation activation energy values, it can be assumed, that Maxwell-Wagner polarization has the biggest impact on the observed dispersion in measured dielectric spectra. Also, in NZF–BT composites the increase of nickel ferrite ratio from 30 to 70 can lead to higher DC conductivity values, higher dielectric losses and higher DC conductivity activation energy. Moreover, in BTS–NF composites, the increase of antimony concentration from 0.1 to 0.5 %mol can lead to higher DC conductivity values, higher dielectric losses and lower DC conductivity activation energy values. |
