Electrical Conduction Mechanism and Dielectric Properties of Spherical Shaped Fe₃O₄ Nanoparticles Synthesized by Co-Precipitation Method.

Adrian Radoń,Dariusz Łukowiec,Jarosław Mikuła,Patryk Włodarczyk,Marek Kremzer

doi:10.3390/ma11050735

Abstract

On the basis of dielectric measurements performed in a wide temperature range (173–373 K), a comprehensive analysis of the dielectric and electrical properties of magnetite nanoparticles electrical conduction mechanism of compressed spherical shaped Fe3O4 nanoparticles was proposed. The electrical conductivity of Fe3O4 nanoparticles was related to two different mechanisms (correlated barrier hopping and non-overlapping small polaron tunneling mechanisms); the transition between them was smooth. Additionally, role of grains and grain boundaries with charge carrier mobility and with observed hopping mechanism was described in detail. It has been confirmed that conductivity dispersion (as a function of frequencies) is closely related to both the long-range mobility (conduction mechanism associated with grain boundaries) and to the short-range mobility (conduction mechanism associated with grains). Calculated electron mobility increases with temperature, which is related to the decreasing value of hopping energy for the tunneling of small polarons. The opposite scenario was observed for the value of electron hopping energy.

Highlights

IntroductionInterest in ferrites is connected especially with their magnetic and electrical properties, as well as their microwave absorption and photocatalytic properties
Many different ferrites containing divalent, trivalent and quadrivalent ions were synthesized [1].Interest in ferrites is connected especially with their magnetic and electrical properties, as well as their microwave absorption and photocatalytic properties
The dielectric properties, electrical conductivity and microwave absorption properties of ferrites are the focus of our research

Summary

Introduction

Interest in ferrites is connected especially with their magnetic and electrical properties, as well as their microwave absorption and photocatalytic properties. Li et al prepared MnZnFe2 O4 nanoparticles (with chemical formula Mn0.8 Zn0.2 Fe2 O4 ) with superparamagnetic behavior, i.e. high magnetization (79.6 emu/g), and small size (15–20 nm) [2]. The dielectric properties, electrical conductivity and microwave absorption properties of ferrites are the focus of our research. This phenomenon is associated with the possibility of using ferrites as electromagnetic interference shielding materials (especially as microwave absorbers), which is related to the their high reflection loss [3,4]. The effect of substitution of ions on dielectric properties and electrical conductivity has already been described for MnFe2 O4

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Conclusion