Effect of SiO2 a
Effect of SiO2 addition on the electrical properties of Ni-doped Cu-Cr ferrites
El- Kony D.
Physics Department, Faculty of Science ,Tanta University ,Tanta ,Egypt. email@example.com
Abstract: Ferrite samples having the composition (Cu1-xNixCr FeO4; x = 0.2, 0.4, 0.6 and 0.8) was prepared using the usual ceramic technique. Then composites of these ferrites with SiO2 were prepared by mixing 25% weight of SiO2 powder with 75% weight of each composition of the ferrite powders. The dc conductivity and the dielectric properties of the samples were investigated. The dielectric constant (ɛ′) and ac conductivity (σʹac) were measured at different frequencies and temperatures. The variation of the ac conductivity with temperature shows semiconducting behavior, whilst with frequency it shows almost constant values over a wide range especially at high temperatures and a slight increase with increasing frequency at lower temperatures. This behavior indicates that the studied composites may be good candidates for many applications. The dielectric constant shows some broad peaks which shifts to higher frequencies with increasing the temperature. These results are explained as due to the existence of two types of charge carriers (n and P) in Cu containing ferrites. The algebraic sum of their contribution to the polarization gives rise to those peaks. The results show that adding silicon dioxide has reduced the conductivity significantly or in other words increased the resistivity of the material, which improves the dielectric properties of the system to be used in applications that requires very low levels of eddy currents.
[El- Kony D.. Effect of SiO2 addition on the electrical properties of Ni-doped Cu-Cr ferrites] Journal of American Science 2012;8(10):697-705]. (ISSN: 1545-1003). http://www.jofamericanscience.org. 94
Key words: Dielectric Properties; DC Conductivity; Soft Ferrites. Full Text 94