Nanoparticles of Li_0.3Zn_0.3Co_0.1Fe_2.3O₄ are prepared by sol-gel method using nitrate salts as precursor materials. Two different sizes (16.9 and 38.9 nm) are obtained by annealing the sample at 500 and 600 °C, respectively. X-ray diffraction (XRD) patterns of the two samples exhibit only the desired peaks of cubic Fd3m space group which confirms the pure spinel ferrite phase formation in the samples. Size and root mean square (r.m.s.) lattice strains are obtained by Williamson-Hall method. The r.m.s. lattice strains of the two samples are 1.25 x 10^-4 and 1.15 x 10^-3, respectively which confirms that the prepared samples are free from appreciable defects. The dielectric constants of the two samples are studied as functions of temperature and frequency. Dielectric behavior of the samples is explained by the electronic exchange between ferrous and ferric ions. Thermal variation of the dielectric constant shows that there is a phase transition from ferroelectric to paraelectric phase for both the samples at ~ 320 K. Dielectric constant decreases with the increase of frequency which is since beyond a certain frequency of the externally applied electric field, the electronic exchange between the Fe2+ and Fe3+ ions fail to follow the applied electric field.

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