Mössbauer studies of Zn_0.05Fe_2.95O₄ nanoparticles

Nanoparticles of spinel ferrite (Zn_0.05Fe_2.95O₄ ) were prepared using the process of high- temperature thermal decomposition (HTTD) and were treated with an Ar plasma for 30 min. The crystal structure was found to be cubic spinel with space group (Fd-3m). The lattice constants of Zn_0.05Fe_2.95O₄ before and after the plasma treatment were found to be 8.3862 and 8.3853 Å, respectively. The saturation magnetization value increased from 69.1 to 73.5 emu/g after the plasma treatment of the Zn_0.05Fe_2.95O₄ nanoparticles. The Mössbauer spectra before and after the plasma treatment of Zn_0.05Fe_2.95O₄ were analyzed at 4.2 K using four sextets. As the temperature was increased, the lines of the Mössbauer spectra broadened due to a fluctuation in the anisotropic hyperfine field. The Mössbauer spectra were found to have the same anisotropic field fluctuation of +H (P₊ = 0.5) and −H (P₋ = 0.5). The relaxation frequency factor, f, was also calculated from the Mössbauer spectra.