Synthesis of nano-NiXFe2O4 (X = Mg/Co) by citrate-gel method: structural, morphological and low-temperature magnetic properties

Abstract

A series of Mg-doped NiFe2O4 (NMF) and Co-doped NiFe2O4 (NCF) nanoparticles were synthesized via citrate-gel method. The X-ray diffraction patterns of conventionally heated NMF and NCF nanoparticles confirmed the formation of single-phase cubic spinel structures. Further, the variation of structural parameters as a function of compositions was described. The morphology of NMF and NCF materials was investigated using scanning and transmission electron microscopes (SEM and TEM). In addition, the formation of tetrahedral (A-site) and octahedral (B-site) locations of NMF and NCF was obtained from the Fourier transform infrared spectra (FTIR). Furthermore, the room- and low-temperature magnetic properties were studied for NMF and NCF nanoparticles using magnetization versus magnetic field (M-H) loops and zero field cooled (ZFC) and field cooled (FC) curves, respectively. The results revealed that NMF and NCF nanoparticles exhibited superparamagnetic (SPM) nature at room temperature.