Preparation, Structural and Electrical Properties of Nanocrystalline Zr-Mn Cobalt-Ferrite Synthesized by the Co-Precipitation Method

摘要

The present study describes the preparation, structural and electrical characterization of nanosized Zr-Mn cobalt-ferrites. The nominal compositions CoFe_(2-2x)Zr_xMn_xO_4 (0.1<= x <=0.4) have been synthesized by the co-precipitation method. These nano-powder products were sintered in furnace at temperature of 800 °C for 8 hour with a heating rate of 10°C/min to obtain these ferrites. The nanopowder was evaluated using XRD, FT-IR and SEM. The XRD data showed that all the samples are of single phase and the crystallite size is found in the range of 26-30 nm. The lattice constant (a), X-ray density (dx), porosity (P) and bulk density (dm) are also calculated from XRD data. FT-IR study confirms the presence of ferrite functional groups. The IR spectra of Zr-Mn ferrite system have been analyzed in the frequency range 400-650 cm~(-1) . It revealed two prominent bands υ_1 and υ_2 which are assigned to tetrahedral and octahedral metal complexes, respectively. The position of the highest frequency band is around 550 cmv while the lower frequency band is around 425 cm~(-1). The structural properties are also analyzed on scanning electron microscopy (SEM) at room temperature. Additionally, the dc electrical resistivity decreased with the rise in temperature for all the samples, showing a semiconductor like behavior. From the dc electrical resistivity the activation energy and drift mobility are determined. Both the drift mobility and activation energy increase with a rise in x.