Dielectric Studies of Single and Double Sintered Ni Substituted Li-Zn Ferrite

Abstract

Ni substituted Li-Zn ferrites with compositional formula Li 0.4-0.5x Zn 0.2 Ni x Fe 2.4-0.5x O 4 where 0.02 ≤ x ≤ 0.1 in steps of 0.02 was synthesized by using citrate precursor method. X-ray diffraction was used to confirm the spinel phase. A series of sample was given sintering at 1080°C and another series given sintering at 1080°C after a presintering at a temperature of 600°C. The dielectric constant was investigated as a function of composition and frequency for the two series. Room temperature dielectric constant showed a decrease with addition of Ni 2+ ions. It was explained in terms of space charge polarization and koops two layer model. For both the series the variation in dielectric constant with frequency showed dispersion. The possible mechanism responsible for the above behavior is being discussed.