Impact of palladium ions doping on structural, magnetic, and electromagnetic properties and hyperfine interactions of Co-Ni nanospinel ferrites

Abstract

Pd2+ ions substituted Co-Ni spinel ferrites nanoparticles (Co0.5Ni0.5PdxFe2-xO4 (Pd -> CoNiFe2O4) NSFs) have been synthesized via a hydrothermal route assisted with polyethylene glycol (PEG). XRD, SEM, TEM, HR-TEM, VSM, and Mossbauer spectroscopy were used to provide a thorough analysis of the phase and structure, magnetic characteristics, and hyperfine interactions. Magnetic features of prepared NPs showed ferrimagnetic behavior. In comparison to non-doped NPs, the incorporation of a small amount of Pd ions within Co0.5Ni0.5Fe2O4 provoked initially a slight rise in magnetization and coercivity magnitudes. Furthermore, as the Pd2+ ions content continued to increase, magnetization and coercivity exhibited a diminishing trend. These observations are explained by changes in size and morphology, variations in the strength of superexchange interactions, and cation redistribution. M & ouml;ssbauer spectra for all samples exhibited four distinct magnetic sextets. The doped ions were substituted with Fe3+ ions at B site. The cation distribution was ascertained through the utilization of Mossbauer spectroscopy. An investigation of electromagnetic (EM) properties was conducted within 2-18 GHz. EM characteristics of the samples can be explained by the main contribution in EM absorption from the electric energy losses.