Abstract
In this study, we substituted the magnetic Fe3+ ions with highly paramagnetic rare earth Dy3+ cations in MnFe2O4 spinel ferrite nanoparticles to investigate the physical, structural, spectral and electrical properties in detail. Dysprosium substituted inverse spinel ferrite nanoparticles (DyxMnFe2-xO4) (0 ≤ x ≥ 0.16) were prepared via facile optimized wet chemical approach i.e. micro-emulsion route. Substituted and unsubstituted manganese ferrite nanoparticles were annealed at 400 °C for 4 h under vacuum. X-ray diffraction (XRD) analysis proved the spinel structure of all compositions of DyxMnFe2-xO4 nanoparticles. Various physical parameters were calculated from XRD data. Quantitative measurements of cations distribution were carried out to estimate the distribution of divalent metal cations (Mn2+) and trivalent metal cations (Fe3+ and Dy3+) between A-sites (tetrahedral) and B-sites (octahedral). Oxygen parameter ‘u’ was calculated to study the displacement of oxygen ions in tetrahedral sites along (111) direction. Fourier transform infrared spectra (FTIR) were recorded to study the two significant absorption bands corresponding to A-site and B-site. Scanning electron microscopic (SEM) analysis was carried out to study the morphology of DyxMnFe2-xO4 nanoparticles. After structural and morphological investigations, all compositions of DyxMnFe2-xO4 nanoparticles were subjected to dielectric parameters measurements. The dielectric parameters like dielectric constant (real and imaginary part) and tangent loss were investigated as a function of frequency from 1 MHz to 3 GHz at room temperature.