Effect of binary mixture of Nd–Zn ions on the electrical, structural and dielectric behavior of calcium-barium M-type hexaferrite nanoparticles

Abstract

This study reports the synthesis and characterization of Nd–Zn-doped nanocrystalline Ca0.5Ba0.5-xNdxZnyFe12-yO19 (x = 0.00–0.10; y = 0.00–1.00) hexaferrites prepared by sol–gel auto combustion method. Doping of the binary mixture of Nd–Zn enhances the electrical and structural properties of Ca0.5Ba0.5-xNdxZnyFe12-yO19 hexaferrite nanoparticles. The required annealing temperature was obtained on the basis of TG/DTA analysis. The results of X-ray diffraction patterns revealed that dopant contents are inversely related to lattice parameters. The average nanocrystalline size lies in the range from 16 to 29 nm. The DC electrical resistivity decreased, whereas the drift mobility was increased by increasing doping of Nd–Zn. Maxwell–Wagner and Koop’s models were used to explain the dielectric constant and dielectric loss versus frequency. Nd–Zn doping favored the decrease in dielectric losses to a large extent, so the barium hexaferrite along with these dopants is very useful for high frequency applications. AC conductivity at low frequencies explained the grain boundary behavior; however, the dispersion at high frequency may be attributed to the conductivity of grains. The M–H loop indicated that the coercivity changed as a result of increase in grain size and saturation magnetization was increased as a result of strong and magnetic cations distribution on interstitial sites.