Title: Studies on AC and DC electrical conductivity and thermo-electric power of NiMgCuZn ferrites

Authors: Narla Varalaxmi, K.V. Sivakumar

Addresses: Department of Physics, Kakatiya University, Warangal – 506009, India. ' Ceramic Composite Materials Laboratory, Department of Physics, Sri Krishnadevaraya University, Anantapur – 515 003, India

Abstract: Three series of NiMgCuZn ferrites viz: 1) Ni_xMg_0.6−xCu_0.1Zn_0.3Fe₂O₄ with x = 0.0, 0.1, 0.2 and 0.3; 2) Ni_0.3Mg_xCu_0.1Zn_0.6−xFe₂O₄ with x = 0.1, 0.2 and 0.3; 3) Ni_0.35Mg_xCu_0.05Zn_0.6−x Fe₂O₄ with x = 0.0, 0.1 and 0.2 were prepared by conventional ceramic double sintering process for studying their stress sensitivity with a view to use them as core materials for micro-inductor applications. The formation of single phase was confirmed by X-ray diffraction. The temperature and compositional dependence of DC and AC electrical conductivities (σ) and thermo-electric power (α) were studied in these three series of polycrystalline ferrospinels. The studies were carried out in wide range of temperature from 30°C to 360°C. On the basis of thermo-electric study, the ferrites under present work were found to show both n and p type conduction. The electrical conduction in these ferrospinels is explained on the basis of polaron hopping mechanism.

Keywords: ferrites; microinductor application; electrical conductivity; thermoelectric power; polaron hopping; nickel; magnesium; copper; zinc; stress; polycrystalline ferrospinels.

DOI: 10.1504/IJNP.2010.037147

International Journal of Nanoparticles, 2010 Vol.3 No.4, pp.349 - 366

Received: 11 Feb 2010
Accepted: 06 Jun 2010
Published online: 27 Nov 2010 *

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