Effect of precursors on dielectric properties of Co-Zr doped strontium hexaferrites in 20 Hz – 120 MHz frequency range

ABSTRACT

Cobalt and zirconium doped ferrite pellets of composition are synthesized successfully using the sol-gel method with two different precursors: Citric Acid and Tartaric Acid. Dielectric constant and dielectric loss tangent measurements are performed in the frequency range 20 Hz − 120 MHz over Impedance analyzer. A.C. conductivity is calculated from Debye's equation of complex permittivity. Dielectric constant and loss tangent are found to be varying in accordance to Maxwell-Wagner theory of interfacial polarization. A.C. conductivity is found to increase with increase in frequency as well as doping amount. Dielectric analysis of two series concludes that ferrites prepared using tartaric acid have higher values of dielectric properties at lower frequencies in comparison to those prepared with citric acid, while at higher frequencies, the effect of precursors seems to be insignificant. The enhancement of dielectric constant and dielectric loss with increase in dopant concentration suggests that these samples are promising materials for applications in microwave devices.

KEYWORDS:

• Strontium hexaferrites
• dielectric constant
• loss tangent
• A.C. conductivity