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a b s t r a c tThe magnetic and physical properties of ferrites are very sensitive to microstructure, which in turn critically depends on the manufacturing process. In this study, nickel zinc ferrite powder with composition Ni 0.8 Zn 0.2 Fe 2 O 4 has been prepared via conventional ceramic processing and co-precipitation methods. The toroidal and pellet form samples were sintered at various temperatures such as 1100, 1200 and 1300 1C. The microstructure, magnetic and dielectric properties of both samples were studied. The X-ray diffraction patterns confirm the formation of single-phase cubic spinel structure for the co-precipitation technique after sintering. The microstructure studies of Ni 0.8 Zn 0.2-Fe 2 O 4 show the grain size increases and the porosity decreases with temperature for both methods. The controlled permeability with small loss and wide operational frequency range are found in the co-precipitation samples. Dielectric constants decrease with increase of frequency and increase with sintering temperature in both methods. Consequently, the homogenous microstructure with the low-loss high-performance of nickel zinc ferrite has been discovered by means of co-precipitation method.

a b s t r a c tThe polycrystalline Ni-Zn ferrite powder with the chemical formula Ni 0.8 Zn 0.2 Fe 2 O 4 has been synthesized using co-precipitation route. The toroidal and pellet form samples were sintered at various temperatures from 700 to 1300 • C/5 h in steps of 200 • C. The structures of samples were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and the energy dispersive X-ray spectroscopy (EDXS). The magnetic and dielectric measurements were carried out using a vibrating sample magnetometer (VSM) and the impedance analyzer, respectively. The highest density of 4.48 g cm −3 was obtained for the sample sintered at 1300 • C. It was found that the initial permeability increased from 4 to 17 and the RLF was in the order of 10 −3 to 10 −4 in the frequency range of 1.0 MHz to 1.0 GHz. The dielectric constant and dielectric loss were lower compared to the reported values for conventional solid state technique. The electrical resistivity is in the order of 10 8 cm. Therefore, low relative loss factor and high resistivity make these ferrites particularly useful as inductor and transformer materials for high frequency applications.

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