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Abstract
Samples of disk shaped from unknown commercial ferrite were produced. Structural investigations were performed to recognize the constituents, chemical formula, crystal structure, lattice constants and microstructure of the investigated ferrite . In addition IR spectroscopy examination has been accomplished to scrutinize the occupation of the sublattices of the ferrite. Assumption of the cation distribution has been conferred. Comparison between calculated and experimental lattice constant ratifies the validity of the suggested cation distribution. Dc conductivity measurements for the studied ferrite have been attained at room and elevated temperatures up to 675K. Anomalous trend was noticed in the temperature dependence of the Dc conductivity.
On the basis of magnetic transition such anomaly has been accounted for. According to the Seebeck coefficient measurements, the ferrite behaves as an n-type semiconductor. Moreover the density of charge carriers has been evaluated at different temperatures. Such measurements enabled the determination of the activation energy and mobility of charge carriers. Ac measurements, including Ac conductivity, dielectric constant, dielectric loss and loss tangent were carried out over a wide range of temperature and applied field frequency.
Regarding the Ac conductivity measurements, the Ac activation energy, frequency exponent factor and the relaxation time were revealed. On the other hand, the conduction mechanism in the ferrite was suggested to be small polaron quantum mechanical tunneling. Finally rods of commercial ferrite under investigation were launched in VHF-UHF antenna application.