The study of temperature dependent structural and elastic properties of Ni_0.5Zn_0.5Gd_0.05Fe_1.95O₄ ferrite nanoparticles

The ferrite nanoparticles of composition Ni_0.5Zn_0.5Gd_0.05Fe_1.95O₄ were prepared by sol-gel method. In order to study the temperature dependent structural and elastic properties, the prepared powder was divided into five parts. The first part was considered as the as-prepared sample and the remaining four parts were calcinated at temperatures 600, 700, 800 and 900℃. The X-ray diffraction patterns confirmed the formation of cubic spinel structure in single phase and Fd3m space group without any impurity peaks. The crystallite size was found 17.61 nm in case of as-prepared sample whereas it was increased from 11.75 nm to 18.13 nm with the increment of calcination temperature from 600 to 900℃℃. The lattice parameter was found maximum, 8.389 Å in case of as prepared sample whereas it was found decreased to 8.360 Å with the increment of calcination temperature. From the FE-SEM micrographs, the average grain size was found 100.2 nm in case of as-prepared sample whereas it was found increased to 152.3 nm with the increment of calcination temperature. The FTIR spectroscopy showed six absorption peaks in the range 350 to 3450 cm^-1. The first two absorption bands were found in the ranges 360–448 cm^-1 and 553– 575 cm^-1 which attributes the presence of spinel structure. The study of elastic properties was made by measuring the longitudinal velocity (V_l) and shear velocity (V_s) which were carried out at room temperature using pulse transmission technique at the frequency of 1 MHz. The elastic moduli were found increased with the calcination temperature whereas zero porous moduli were found decreased with the calcination temperature. key words: XRD, SEM, FT-IR, Elastic Moduli