Permittivity Relaxation Variation for Additive Doping in Cobalt Ferrite at High Frequencies

Abstract

We present a comparative study of the variation in dielectric relaxation for the additives SiO₂, TiO₂ and ZrO₂ in cobalt ferrite. CoFe₂O₄ was prepared using microwave hydrothermal system and sintered at 900 °C/30 min using microwave sintering method. Real and imaginary parts of permittivity were measured in the frequency range of 1 MHz to 1.8 GHz for these samples. A shift in the dielectric relaxation towards higher frequencies for doped samples is observed as expected in percolating systems. A non-linear least square fit of the electron oscillator model is used to parameterize absorption in the samples.

Keywords:

• Ferrites
• cobalt ferrites
• complex permittivity
• additives

Note

Prof. S. R. Murthy, one of the co-authors in this paper passed away on September 5,2019. Prof. S. R. Murthy worked as Professor in Department of Physics, Osmania University, Hyderabad. He was a prolific researcher in the fild of materials science and had retired in 2011. He has guided several students for doctoral degrees and has authored many articles in reputed journals.