Structural, magnetic and electrical properties of the sol-gel prepared Li0.5Fe2.5O4 fine particles

• Published in: Journal of physics. D, Applied physics Vol. 39; no. 5; pp. 900 - 910
• Main Authors: George, Mathew, Nair, Swapna S, John, Asha Mary, Joy, P A, Anantharaman, M R
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 07.03.2006; Institute of Physics
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Dielectric properties of solids and liquids; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronic transport in multilayers, nanoscale materials and structures; Exact sciences and technology; Magnetic properties and materials; Magnetic properties of nanostructures; Nanocrystalline materials; Permittivity (dielectric function); Physics; Grain size; Frequency dependence; Lithium oxides; Electrical conductivity; Magnetization; XRD; Heat treatments; Ferrites; Nanoparticles; Fine particle; Coercive force; Iron oxides; Permittivity; Sol-gel process; Saturation magnetization; Magnetic properties
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/39/5/002

Fine particles of lithium ferrite were synthesized by the sol-gel method. By subsequent heat treatment at different temperatures, lithium ferrites of different grain sizes were prepared. A structural characterization of all the samples was conducted by the x-ray diffraction technique. A grain size of around 12 nm was observed for Li0.5Fe2.5O4 obtained through the sol-gel method. Magnetic properties of lithium ferrite nanoparticles with grain size ranging from 12 to 32 nm were studied. Magnetization measurements showed that Li0.5Fe2.5O4 fine particles exhibit a deviation from the predicted magnetic behaviour. The as-prepared sample of lithium ferrite showed a maximum saturation magnetization of 75 emu g-1. Variation of coercivity is attributed to the transition from multi-domain to single domain nature. Dielectric permittivity and ac conductivity of all the samples were evaluated as a function of frequency, temperature and grain size. Variation of permittivity and ac conductivity with frequency reveals that the dispersion is due to the Maxwell-Wagner type interfacial polarization.