Structural And Electrical Behaviour Of Sol-gel Derived Li-Ni-Co Ferrite/SiO2 Nanocomposites
Nandeibam Nilima, Mamata Maisnam, Sumitra Phanjoubam
Volume 2, Issue 5, Page 310-314, Year 2017 | DOI: 10.5185/amp.2017/506
Keywords: Ferrites, sol-gel, XRD, SEM, dielectric constant
Abstract: Li-Ni-Co ferrite/SiO2 composites with representative formula Li0.41Ni0.1Co0.08Fe2.41O4+ xSiO2 (i.e., x = 0wt. %, 5wt. %, 10wt. % and 20wt. %) were prepared by sol-gel method. The prepared composites were pre-sintered at 600ºC for 2 hrs and then finally sintered at 1000ºC for 6 hrs. X-ray diffraction studies showed diffraction peaks indicating single phase with spinel structure. However, peaks of SiO2 were found in composites of higher (x). The microstructure of the samples was studied by using Scanning Electron Microscopy. The crystallite size and average grain size were found to decrease with increase of SiO2 content. The room temperature frequency variation of dielectric constant and dielectric loss was measured from 100Hz-1MHz and they showed a dispersive behavior. The variation has been explained by Verwey mechanism of electron hopping and Koop’s two-layer model. The addition of SiO2 plays significant role in influencing the various structural, microstructural and electrical properties. Uniform and refined microstructures are observed with the addition of SiO2 and this reduces the value of dielectric constant and loss significantly, which is desirable for high frequency applications. The results obtained and mechanisms involved are discussed. Copyright © 2017 VBRI Press.